Why so many processes upon wakeup from Sleep?

I've seen this on my primary deskside machine and my laptop... when the
machines resume from Sleep, the number of running processes jumps way up
for a few minutes. It then declines, but never back down to the number
I'm used to seeing after a power-on boot. The deskside machine usually
starts up with about 120 processes according to Task Manager when first
booted; the laptop is around 90. After resuming from Sleep, the deskside
will show upwards of 150 processes, the laptop around 120. After a few
minutes, the numbers are down to about 130 and 100 respectively. One
thing I notice on both machines is that TrustedInstaller runs and
consumes quite a lot of resources for a few minutes - why does it run
after Sleep?

Jason