Not had any problem with mine, or anyone else I know with a PS3.
Besides if you're worried about reliability, why is the 360 even being mentioned in the same sentence as the PS3?
Yes, the next-gen consoles are a long way off. The next big movement in entertainment changes is 3D, which the PS3 is supposed to fully support. I'm almost certain MS will release the next one before Sony, but I don't see the need to replace the PS3 for the foreseeable future. I expect the current series of next gen consoles to have a much longer life time. I wouldn't be surprised if it was 8 years between PS3 and PS4.