While I'm going to say that what happened to me over the past couple of days concerning the new version of STEAM and the gigantic TF2 update is generally inapplicable to the majority of STEAM users, seeing how the STEAM forums are pretty calm, I'm still pretty damn annoyed at my situation right now.
 
If you're a college/university student, you would know exam season just came to a close today.  Being a university student, I was slaving away at my studies, preparing for exam and finishing papers, and occasionally putting Team Fortress 2 on idle servers so I wouldn't miss out on random items with the recent rise given to drop rates. On Monday of this week (April 26th), the new version of STEAM was released.  I didn't get the chance to update until Wednesday, and when I did try to run STEAM, the application launched into the update sequence, telling me that it was updating and would be finished soon so I would be able to enjoy the "new STEAM experience."  This would have been great if STEAM wasn't lying to me.  Instead of upgrading to the new STEAM, it killed my old STEAM by removing Steam.exe.  Now I don't know why this happened.  I'm going to guess it's not supposed to happen, but it happened to me.  I was left wondering what the Hell was going on and why my STEAM was not launching when I clicked on the STEAM icon.  All I got out of clicking STEAM was Windows telling me that it was looking for Steam.exe and wasn't finding it.  Uh.....?
 
After roughly 30 minutes of confusion, I decided to just re-install STEAM, a process that would normally be pretty expedite if the "update" didn't completely break my old STEAM.  Long story short, removing STEAM through control panel didn't work, so I had to do it manually.  Content that a fresh install would fix my problem, I downloaded STEAM through the web (via Googling for the app, b/c the official site apparently didn't provide any links to it on its main site.  I looked, I really did...) and reloaded it.  This worked, STEAM ran again (hooray!).  Now I was dealing with a new problem.  New STEAM would not detect my game installs.  What?
 
The solution to this new problem was straightforward enough after I realized why new STEAM wasn't detecting the games.  New STEAM installed into its own folder "C:\...Program Files\Steam" instead of my old "C:\...Program Files\Valve\Steam", maybe it's because I originally acquired STEAM via TF2's install disks instead of the Web.  This is a little weird, but whatever, a quick move of game files between folders fixed this.  I would go on to enjoy some TF2 on Thursday, albeit with super bad ping (200+) whose cause I could not pinpoint (this resolved itself later that night, so it's clearly some sort of network issue on Valves end).
 
The worst happened to me tonight (April 30th), after I started up STEAM and it updated TF2.  TF2 just straight up broke.  I couldn't connect to servers.  Well, technically I could connect, but I would get booted out to the server browse immediately after.  I could create my own server, but couldn't join others.  A quick peek in the console told me there was some sort of issue about my client missing some files.  I verified my game files and looked around online for solutions to this, but nothing.  Absolutely nothing.
 
Now I'm in the process of re-installing TF2.  As of April 30th, 10:22 PM PST, it is sitting at 60%.  It's been four hours since I started downloading.  Fucking A'.

Happened to Left 4 Dead 2 but shit happens.

TheMustacheHero can't even go into the Steam store with the new update, so just be lucky you can at least get to your games.

I've had it freeze on me numerous times while installing all the Rockstar Pack games (40 bucks is a steal though!).  I've also had it suddenly lose connection to the DL server even though my internet it working just fine.

And that's why I prefer gaming on Consoles. Less of this.

I get this shit when I try to even run steam...The OLD steam never had this problem. Fuck you Valve.

Still downloading here.  At 68% now.  Seems like STEAM client now also lies about download speeds.  In the actual app window it's showing 200KB/s+ download speeds, while hovering the mouse over the taskbar icon shows the real download speed which is at around only half of what's showing in the app window.  If the 200KB/s speed is true I would've been done ages ago.  Ugh.

I don't know what's up. I downloaded STALKER and got an average 1.5MBPS.

That's the kind of speed I used to get.  Stopped happening a while back....