ALERT. No matter what happens in April - and I agree FCS 6 is likely - you need to take advantage of Apple's
once in a lifetime offer to go from FCP 4/4.5 HD PPC or any component of the PPC Final Cut Production - including upgrade versions - to the full FCS 5.1 UB for only $199. The upgrade from FCS 5.1.2 UB to FCS 6 will still cost a lot less than it will if you don't go to FCS 5.1.2 UB for $199 by March 20. This offer was supposed to end December 20. But Apple is bending over backwards to extend the offer for three more months through this winter. Anyone who has the old software and doesn't plunk down the $199 for the upgrade is making a big mistake.
There is no upgrade from Final Cut Express to Final Cut Studio 5.1 UB. The upgrade from FCE to FCP has been discontinued iMacZealot. You missed the window of opportunity to do that. If you had, you would have been able to go from your FCP to FCS UB for only $199. But that time is gone. Sorry.
NOTE: $200 rebate on Final Cut Express HD, when you buy a new Mac with it, expires Tuesday March 27. Looks like a date we might expect something new to show up. Wonder what it will be? Like Leopard?

Just guessing.