I'm still tracking this as we get towards February, but I'm now 50/50.
There was a point I was pretty much sold, and I'm away on holiday the following week and fancied a bit of Uncharted on the beach.
The lineup at release looks good, and may well improve as a few third party titles are added to the list.
However my big gripe, and the thing most likely to stop me buying on day one is the memory cards. They are proprietary for the Vita, needed for some of the games, including Uncharted and are the prices are absurd. A 4GB is around $30, a 32gb about $120. That's way more than any other memory format around to the point of just being bizarre, it's not even close.
It basically takes the cost of the Vita from £230, which would tempt me to £250+ which starts to put me off.
You can also bet that the UK prices for memory will align with the dollars the US pay!
I'm just hoping people like HMV do some decent bundles which give a better deal on launch.