Be careful if anyone uses cisco vpn software on their current mac and then upgrades to Tiger. The two don't work together. So if you have a Mac laptop you use for traveling and connecting back to your office via cisco vpn, you might want to wait a couple weeks before updating. Cisco says they'll have a fix by then. I ran into this today when a very high up guy at my work decided to update his home computer and now he can't access the network on weekends.
Here's an article about it:
Cisco Reports VPN Conflict with Tiger