I've seen some people say that someone working at Steam said that it will allow you to keep them, but I cannot find a primary source of this. Also the T&C's say that you only have a license of the game and you don't own it, meaning you games can be taken if Steam wants to without breaking the law.

How long have you been waiting to bust that one out?

Pretty much this.

I worry that all these major online game providers will go out of bussiness, resulting in the inability to download hundreds of games that are connected to my accounts. I'm sure someone would take the torch though, and replace the service. 

I dont worry. I dont use steam. xD

No company lives forever. Unless overtaken by a competitor, you loose access to all your games, this is what happens with all DRM systems.

I think they will always exist but will gradually become insignificant.
The major publishers will make their own networks like EA made origin and steam will be left with indies and minor publishers.
I'm surprised MS hasnt challenged steam seriously with games for windows. Sony bringing the SEN for PC content is also a possibility.

It is just a matter of time until Facebook buys them.

We will get HL3 before steam runs out of steam

honestly sort, of... The thing with PC, is communities will always, crack, patch or whatever things.
The game will be available in some form. And the steam files will be available as long as you don't delete them.

It could happen. But a PS3 dieing and Sony going out of business could happen too.

you don't own your PS3 games either. Those are only a license as well.

Ofcourse the government isn't going to come to your house and take your games. While doing the same thing with digital distribution is easier.