As g-bebe points out if you already have HL2 and episode one you end up getting a couple of codes for the aforementioned games, which you can give away to friends. Fairly obviously, all my gaming friends have already played them. Still, the deal on offer is decent, buying episode two, portal and TF2 individually would run to way more than the orange box.
Fortress forever is also worth keeping an eye on. The main problem I have with it is that it's not Team Fortress 2. They have also left concussion jumping in (that seems to be their one of their main aims), which is a pretty weird thing for a new player to get to grips with. There's a gameplay video
here.
The release date for the orange box is 10/10 so we don't have too long to wait now. Of course if you grab the orange box on preorder (via Steam) now you can sign up for the TF2 beta which starts on Monday. I'll be there!