1.d4 d5 2.Nf3 (instead of c4)

Since you've argued with dpnorman even though I agree with him and I fully believe that you implied that c6 was inferior, let me try a different angle:

You say it delays the Slav/SSlav because Black shouldn't play c6 immediately (whether you think you said that or not), but the whole concept fails because Nf6 plays both of these openings so what you say doesn't really make any sense at all. You don't reach some kind of strange delayed Slav or delayed Semi-Slav positions from this move order. You just transpose so I don't know what you're talking about.

I half expect you to come back with the same nonesense to him that you just did above and say that you never said anything about avoiding the regular Slav, so I ask you:

In what way is it better for White to play this "delayed" (not delayed) Slav/SSlav move order. Of course like said above c6 is a fine move so not only have you not forced anything, but what you're claiming that you've forced is just a basic transposition with no benfit for White whatsoever.

So what is your point exactly?

P.S. c6 there doesn't even look weird anyway...

I wish this thread was going more seriously.  I always wondered about this specific move order myself (1.d4 d5 2.Nf3); it's very common but I could never figure what transpositional advantage it conveyed.  You lose the option for several strong variations (e.g, QGD Exchange, KID Samisch, etc.), but you don't seem to get much in exchange, since White is almost certainly going to play c4 at some point anyway.

2. Nf3 takes the pressure off Black and doesn't set up a point of tension  on move 2. While not bad, it's also not particularly challenging to Black and allows him to maybe be a bit more aggressive.

If Black plays 1...e6, keeping options open, Nf3 is even lamer.

I agree with jengais, once d5 has been played there is no particular point to delaying c4 with Nf3. A lot of club players avoid playing c4 until they see d5, that has some point. 

1.d4 Nf6 2.Nf3 avoids the Budapest, the Benoni, and the Benko.  It also gives White the option of playing an alternate system against 2...e6, such as the Torre or London, to avoid the Nimzo.

1.d4 d5 2.Nf3 avoids the Albin, some Queen's Gambit Accepted lines (e.g. 1.d4 d5 2.c4 dxc4 3.Nf3 a6), and gives him the option of finachettoing before playing c4 against certain openings (for instance after 2...Nc6 or 2...e6).  1.d4 d5 2.Nf3 Nc6 3.Nbd2 is also not a bad move.

Well 1. d4 d5 2. Nf3 a6!? isn't exactly a great move, but there's nothing terribly wrong with it 

Sure, although after 3.Bf4 the a6 move seems a little out of place!

Seriously, it is hard to find reasons for 1.d4 d5 2.Nf3.  Much easier to find reasons for 1.d4 Nf6 2.Nf3 and for 1.Nf3.  I think the most compelling reason is (on 2...Nc6) the ability to delay c2-c4 and avoid the Tchigorin mainlines.  The Tchigorin is still a respectable defense, yes?

I agree with the above; 1. d4 d5 2. Nf3 isn't very logical to me unless you're aiming for some non-c4 system. 

boom. most high-level GMs/commentators note that playing d4, c4, Nf3 is designed to avoid the Nimzo, which is apparently doing well for Black at elite levels.

1.d4 Nf6 2.Nf3, what do you play if you want a Benoni?  If 2...c5 3.d5 White may leave his pawn at c2, intending Nc3 instead.  (3.c3 and 3.e3 are also possible, if unambitious.)

Loses the argument.

Says he wins.

Why the needless insult? You are the one who is confused.  Read the immediate sentence before, when I asked you what you would play.  If not 2...c5, what move?

Keep in mind, the Benoni Defense is 1.d4 Nf6 2.c4 c5 3.d5 e6.

1.d4 Nf6 2.Nf3 g6 and White could play 3.Nc3 (Barry Attack), 3.Bf4 (London), 3.Bg5 (Torre) - you will not get a Benoni position against any of these.  And in that last position White usually plays 4.Bg5.

So much for 2.Nf3 not being able to avoid the Benoni.

Unsure why you are being so patronizing. 2...c5 is not a trendy line; it's the sixth most popular move behind Bf5, c6, e6, Nc6 and Nf6. 

I see now it avoids 1.d4 d5 2c4 e5 the Albin Countergambit, and that's it.

I see no point participating in a debate that is needlessly personal and where every barb can be fully addressed by something I already said.  Find someone else to call a kid, dipshit.

Back to the original topic...

@TwoMove, it also mitigates 1.d4 d5 2.c4 Nc6, since on 1.d4 d5 2.Nf3 Nc6 White has good moves other than 3.c4 (e.g. 3.g3, 3.Nbd2, 3.Bf4) that deny Black access to the normal sharp lines.  But other than that, yeah - there is little point, unless White actually wants to play the Colle, or will play the Colle against certain 2nd moves.

Not true!  First off, the "Closed Benoni" and "Schmid Benoni", which are lines where white specifically does not play c4, are better for White than the main lines where c4 has been played.

The Closed Benoni is 1.d4 Nf6 (it can also come from 1...c5 lines) 2.Nf3 c5 3.d5 e5 4.Nc3 d6.  Notice that c4 is not played.  The Knight on f3 is going to go to d2 and c4!  With a pawn there, that's not possible.  With the pawn there, this would be a Czech Benoni, not a Closed Benoni.

The Schmid Benoni, also known as the half benoni, is the modern benoni rather than the Czech Benoni WITHOUT c4 by White, which again favors White!  After 1.d4 Nf6 2.Nf3 c5 3.d5 e6 4.Nc3!  Once again, c4 is open for White pieces.

So yes, there is the benefit of avoiding main line benoni lines by playing 2.Nf3.  The key is not to play c4, but rather, Nc3.

Sorry to play thread necro, but I just got back, and noticed all the replies here.  I still have a hard time believing that GMs are that concerned about avoiding the Albin countergambit and the Chigorin.  I guess it will just remain a mystery...

I imagine that controlling the centre and developing quickly are important chess principles.

Therefore if I was playing a game of chess that started 1.d4 d5 I might think to myself ...hmm today do I think controlling the centre or developing quickly is more important in this position.

I would not really reach a conclusion exactly but on the days I felt like developing quickly more that controlling the centre I would play 2.Nf3

Somebody's ego is showing! Be nice, now...