The update to the source engine messed with the SDK (Hammer doesn't load). Here's how you can fix it:
1) In your main steam folder, go to \bin
2) Copy the dlls libcef.dll and icud42.dll
3) Paste the dlls in the orangebox\bin folder
- Example: I:\steam\steamapps\<account>\sourcesdk\bin\orangebox\bin
Reload hammer. The sourcesdk itself took a while to load, but hammer started up after that.