I was just wondering what the general consensus was on this gambit, which I first saw a couple of days ago. The question, of course, is- Does black have enough compensation for the pawn?

And the alternative without trading queens:

I love gambits, but this doesen't look sound- I really wouldn't want to trade queens a pawn down, but that's just me and I'm not that strong, maybe a strong player will see something I don't?

Ok, what if 4... Bxd6, and we reach the same development but with queens intact?

I havent seen this before. Personaly i would play 3.Nf3 and transpose to Philidor defence. I think Minzz0 rightly pointed out that trading queens is not the best idea. 4...Bxd6 (instead of 4...Qxd6 ) looks more logical but again i dont see how black get compensation for the pawn. On top of that the bishop on d6 just doesnt look right.

Surely, then, if black has no compensation you should not transpose to the Phillidor but take the pawn, thus being at an advantage?

Well he doesn't know you're going to give away a pawn next move. 

hmm. The second one looks okay to me. I'll try it out in some rapid games.

indeed, if i knew after 3.dxe5 black will play 3...Nc6 i would take the pawn. Unfortunately i wouldnt want to face 3...dxe5 with the prospect of queen exchange and a very dry position.

my point excactly :)