Q:

SQL Server Management Studio (SSMS) 2012: Unusually high memory usage (leaking?) 

1.3GB memory usage.  I'm running Windows 7 Ultimate 64-bit. 
I don't do much - just editing a stored proc (no query running in the background, nor any query result). 
I do notice though, it only happens occasionally - as if some kind of a garbage collection is kicking in then it'll return to its normal (around 100MB). 
Any ideas / workaround / updates ? 

Just an update on this: it seems it doesn't happen anymore in SSMS 2014

A:

It seems that if you turn off IntelliSense, the memory consumption subsides dramatically, and the software becomes much more responsive.   To turn it off, go to Tools -> Options -> Text Editor -> Transact-SQL -> IntelliSense, and un-check the box.   Save your work and re-start the SSMS. 
The major drawback is that you will loose both IntelliSense and Code Outlining.   Quite a bummer, but at least you can leave the SSMS open for days without problems. 
Hope this helps.   Cheers.