I'm guessing I will be echoing a lot of what others have said:

I only buy Steam games when they're on sale. Also, I can't "lose" the game.

That's about it.

I can also chat w/others w/their IM!! :D

If steam was ever forced to shut down they would likely do a patch to make the installed client work in offline mode permanently. Tho even if things went really south for the company it would be what a decade before that would happen?

I doubt they're going anywhere yet, but there's always the chance that someone messes their finances up in a big way (stranger things have happened lately). A lot of big companies have gone bust recently, for one reason or another, so it's illogical to assume that even Valve are completely immune.

If they fold, who's going to be on site to make the patch? Would you come to work after being made redundant? I know I wouldn't.

I don't think we need to fear that just yet though. I've watched Steam grow for the past 5 years or so, and it seems to be nowhere near having trouble. My understanding is that it's racking in a lot of money for Valve and its catalogue has practically exploded in the last year or so. So I'd take any death-of-Steam predictions as a really distant possibility for now.

Indeed, but nothing lasts forever. Personally, I try to stick with discs as much as possible, as I feel that I have more control of their use than with a system like Steam. Not to mention their insistence on charging on a basis of $1 = £1, which is just damned stupid.