A new Steam is on the way. Try the beta today!
User interface overhauls isn't anything new. After all, Facebook users should be accustomed to a ridiculous amount of change. Now it's Valve's turn to give Steam a fresh coat of paint.
An opt-in beta today went live for all Steam users who wish to participate in checking out the new-look Steam.
"We made hundreds of changes to the Steam client as a result of customer feedback on the interface, performance, and functionality," said John Cook, Director of Steam Development at Valve.
The folks at Valve also saw fit to change the rendering engine for the UI, ditching Microsoft for an open source solution.
"We swapped out the Internet Explorer rendering engine with WebKit, which gives us a bunch of size, stability and performance benefits," explained Cook. "This release of Steam leaves us well prepared for another year of strong growth."
Major features:
- Complete overhaul of Steam client UI design to improve discoverability of features and to better expose all the information related to games in your library
- Complete overhaul of in-game overlay UI design to create a richer in-game experience exposing context sensitive information related to the game you are currently playing
- New game details view, presenting a detailed view of all the information for a single game in your library
- New grid view, presenting a graphical view of your game library
- New news page in the store/client/overlay which aggregates from Valve related news sites, official community groups, and third-party gaming news feeds
- New downloads view in the client, making it easier to track your progress downloading new games or game updates
- New Steam store design, including more integrated community features, improved recommendations, and improved video and screenshots viewing (and much more!)
Click here for more details and to opt-in to the beta if you're a Steam user.

So fat I'm the only one that had that problem. Oh well, it teaches me this:
BETA = NOT QUITE READY FOR RELEASE, PROCEED WITH CARE.
I'll bet Richard Stallman hates them saying open source, lol
Also, remember this: always do a hdd back-up of the game files; this way you don't have to re-download it all.
Couple of things they need to work on, though:
-seems a little laggy moving the window and scrolling
-no way to delete categories for games
-no more slim view for the games window
-the artwork for games is great, but all of my mods are looking a little bare. Maybe some way for mod devs to add their own custom artwork or for me to do it myself?
For those that don't know, under file there is a "backup games" program you can run to back up your games to your drive. This is useful for betas or moving your steam folder to a bigger drive.
drag the steamapps folder and your SourceMods folder onto the other drive. Uninstall steam, reinstall on the other drive, and put your steamapps and sourcemods folders back in the steam directory. Problem solved.
This^^