Cannondale Capo

all those generic looking fixies you see around shoreditch with the deep-v's and all that - would they be track-specific or are they again sort of hybrids?

those are either are track-specific frame or simply old road bike that has been converted into a fixed wheel bicycles.

I got a snippet of a review on the Cannondale;

Although the Capo isn't a true fixed-wheel bike - it comes with a freewheel on a flip-flop hub instead of a fixed sprocket - its horizontal dropouts, absence of cable stops and steep angles essentially make it a rider friendly track bike ready for road use.
that's pretty much it, the majority of the OTP fixed wheel bicycles (Giant Bowery, Specialized Langster, Charge Plug, etc.) are designed for the road, i.e. more comfort and forgiving (with the playoff of a less zippy handling than track bike).

you just spend a shitload of money making the Cannondale more zippy when a mere change of frame to a track-specific one can easily make it zippier (but less comfortable on the road).