This occurs only after restarting the system and it looks like this - I click "restart", the system boots, I select my user name on the logon screen, enter password and... I see the dots animating next to "Welcome" for 20 to 60 seconds. No disk activity during that time, it looks like the system is just waiting... for what? It's pretty annoying as it takes away all the fun of having Windows 8 on an SSD
After shutting down the system, logging in is very fast - the start screen shows up almost immediately after entering my password. Also, not all restarts have the long welcome problem - let's say, 2 out of 10 restarts take a long time at the "Welcome" screen.