The PS3 is trying to be as good as (if not better) than the Xbox360. They hope to achieve this in the online part of the system. The PS3 is supposed to have most of the stuff Xbox Live has. Like multiple ways of communicating with friends, downloadable stuff, etc. The PS3 is advertised to include a full web browser (wow, they took that idea from the Wii) and pricing in real $$$ instead of points (which seems to be another reference to the Wii).
Another feature is the parental features, with logging and master accounts and what not.
There is a bank (it’s like a bank system however it seems more like cash on hand than a bank) which you can use to make all your payments for online playing (wow, paying for each individual game rather than one payment for all like other systems)
And then there is the PS3 OS that is upgradable from the Online service that takes up the entire hard drive (thought you could get away from memory cards could you?).
But unfortunately the PS3 will probably will not be like the 360 (much to the dismay of Phil Harrison). You can’t use messages while playing a game (you can only get notified) and if you want to read them you will have to exit the game in order to respond. Sony has yet to state if they will have leaderboards for games.