I have been running my 8100 all through the internet service and we are now going to install the BES at work and i have a couple of questions.

1. can i still get all my personal email pop-ed to my phone?
2. i do not see how i am to activate the BES on my phone, I always thought i had an icon with BES activation but i do not see it now?

Yes you can still setup your personal email to your phone. Make sure you have the BES service on you account otherwise you can setup BES. But if it is on your account and still don't see the icon you can go to Options -> Advanced Options -> Enterprise Activation

Wirelessly posted (My blond BlackBerry)

Yes, you can get all your personal email, but the BES can be configured to block sending email AS the personal account, and can also block it altogether. This will depend on how the IT Policy is configured.

In order to activate on the BES, you need to have an Enterprise BB data plan. A BIS-only cannot be activated on a BES.