So I can add Visual Studio to my steam library, and potentially develop in it from my mac? This is huge, I can now run my PC at home headless since I only used it for games/visual studio.

I would be interested in the other way around, as well.

Could I add XCode to Steam on a Mac and then stream that on my main Desktop?

I know I can hook up my MacBook to an external keyboard and monitors but I have a very... integrated setup for my main Windows Desktop and hooking up my MacBook with those monitors, keyboard would be quite a hassle.

This way, I could keep it on my couch table and still be able to work on XCode on my big Desktop monitor.

Yep! It works great too, just add it as a non-steam game or do one of the workarounds to stream the desktop and then start it from there.

Also consider that software other than games is sold on Steam as well: http://store.steampowered.com/software/

By remote control, do you mean as a VNC/RDP alternative for non-gaming purposes?

I guess so, I've been using it to run Chrome just for the lolz and it works really well. Just add an app to your Steam library, then run it and good chances are that it'll actually start. Sometimes it doesn't but in most cases it works well!

I used to have a Firefox shortcut in my Steam games list so I could watch online video with the Steam overlay. It wasn't flawless, but it worked great most of the time, as long as I didn't try to open the overlay until I was in full screen.