Steps to reproduce the bug: Allow SL to auto-update itself.
Observed results: On Windows, C:\Documents and Settings\<user name>\Local Settings\Temp contains numerous .exe and .tmp files with the SL installer icon. I have 246MB worth of these dating back to 4/25 (when I believe I deleted previous ones).
Expected results: No temp files! A more efficient updater that PATCHES SL instead of mindlessly redownloads the entire client unnecessarily!