unless btc value go up for a couple of hundred dollars more.
Well given the current trend of BTC, this *is* going to happen.
Saddly, the other certainty is that, with the current production of ASIC ramping up, the difficulty will also be exploding.
Currently you have a time to share of 1.3 days (which is not bad, and once you hit this share, P2Pool starts to pay you constantly based [more or less] on your hashrate [I'm over-simplifying])
But in a few weeks, they'll be so many people hashing overall, that the difficulty is going to explode and your time to share is going to climb up to a week or more.
(Each time with payment spiking after a share is found, then gradually fading out).
P2Pool is even more complicated, as its shares are quite difficult and you spent long time with no share and no payment if your own hashrate is too small compared to the whole P2Pool network.
Currently, ASIC mining is hard. The only way to be successful, is to predict in advance which company will be good at bringing next crop of mining hardware the first, with the least delays and least performance problems, and then manage to order among the first and get it delivered soon enough, so you can reap a few bitcoins before the whole difficulty explodes as next generation floods the market. If you picked up the wrong horse (like Butterfly labs, in the current generation :-P ), by the time they ship and you receive, you'll have bought an expensive and noisy space heater.
On the other hand, I you don't mind that much, and aren't interested into making a fucking crazy amount of money, but are more interested into contributing to the network, keep hashing, even if you have a small hashing power, you and all the poeple with small hashing at home, help avoiding that all the hashing power gets concentrated in the hands of a few data-center owner, with cabinets full of 10'000$ ASICs)