That's basically the Sicilian Defense, Nimzowitsch variation. I don't know much about it except the name.
English Nimzowitsch variation - What would you do? 1.c4 e5 2.Nf3

I've been following lines given in 'An Explosive Chess Opening Repertoire for Black', basically as you have with 2..d6, but followed up with an early ..f5.
I'm not sure the independant line of 2...e4 would give Black anything more, chances are White would be a bit more familiar with the intricacies of the resulting positions.
Well the mainline of the Sicilian Nimzowitsch is 1. e4 c5 2. Nf3 Nf6 3. e5 Nd4 4. Nc3 Nxc3 5. dxc3 Nc6 6. Bf4 Qb6 when White has a large lead in devlopment in exchange for the doubled pawns. You should at least look at 1. c4 e5 2. Nf3 e4 3. Nd5 Nc6 4. Nxc6 dxc6. The free piece play seems to be worth it at a glance.

What's the rumbus 1c4 e5 2Nf3 e4 doesn't look much for white as mentioned, and can just ignore it with 2...Nc6.
Never did see the attraction of an explosive rep, or what was particularly explosive about 1.d4 d6 2Nf3 Bg4, but hey ho sold like hot cakes in its time.
Thanks for the info everyone. I'll be getting that book PeskyGnat to see what they say about it as I think that's the set-up I'm going to use.
In a game I played this morning against Rybka set to a medium difficulty, I considered playing e4 Nd4 Nc6 Nxc6 dxc6 but the comp is very good at exploiting pawn weaknesses and I was scared with the perhaps overextended pawn on e4 and the doubled c pawns in the bargain that sooner or later one of them would drop off so I decided to do something solid instead and went with an Old Indian.
Does anyone play or have any knowledge about the English Nimzowitsch variation 1.c4 e5 2.Nf3? What do you think is best for Black to do?
What I've been doing is playing 2...d6 and going into an Old Indian set up. Hoever I wanted to know what is or are considered the most testing lines to use against the English Nimzowitsch variation? The Old Indian is good but White gets an opening advantage and surely there must be an easy line to play against this that equalizes.
Also where are people getting the idea to use this? Is there some book out there about it? I always wonder that about any unusual opening people play.