I own both consoles...so while I may have a more informed opinion, it is still, JUST my opinion...
I pay for live because IMO the interface is easier to use, and has multiple perks that I either can't find (poor design) or don't exist on the PSN. Currently those would include: a party system, voice messages, cross game chat/messaging, friends sorting, a better download system (I downloaded the same game twice on PSN, because I didn't remember downloading it before and unlike Live, it didn't tell me I already had), and Netflix/Twitter/Facebook integration.
BEYOND all of that however I have a long list of friends that I play with on Live and many more mullti-player games that I play on Live (so far my PS3 is a single player only experience).
So in short (or was that long...) nothing the PSN does will stop me from paying for Live. When LIVE ceases to be of use to me I will stop, but it is unlikely the PS3 will influence that much at all. THAT however is just my opinion, I'm sure there are lots of folks on here, with their own.
