Watching from the peanut gallery allows me to say just about anything. So here is my 2 cents.
Apple has had years to consider the required port of Final Cut Studio from the old crusty classic environment to the new Cocoa toolset. One has to assume that they have actually been working on the port unless one thinks that they are going to outright dump their pro apps. When they started and how long it will take is a mystery to the public. I take the positive attitude that they are well into the development process.
Like many others, I expect this will be a full rewrite from the ground up. Using source conversion scripts or other tricks would be very ugly. They'll want to take full advantage of the new toolsets and set them selfs up well for the future.
Apple has been selling only 64-bit hardware for a while now, so I won't be surprised to see that the new FCS is 64-bit only. This would be the perfect time to drop 32-bit support and the extra maintenance issue that come with it.
In iOS 4, Apple introduced the AV (Audio Video) Foundation Framework. I see that being introduced in Lion next summer and freeing them from the crusty QuickTime toolset they are currently using. Sure, FCS will also have private APIs, but this new framework will be heavily leveraged.
Given that pros are seeing advantages in recent iMovie releases, you can be sure Apple is aware of that and there will be a similar and more advanced changes in FCS. Oh, I don't expect them to drop the classic time line as pros require the precision it affords.
I expect the new FCS to require Lion because FCS will take advantage of Lion specific technology. So the earliest you'll see for the new Final Cut Studio will be sometime after the public Summer 2011 release of Lion.
P.S. If you want a full featured Blu-Ray creative package, you'd better let Apple know directly via what ever feedback mechanisms that are in place. Whining on sites like this will not help. Perhaps some interested party needs to organize a massive feedback day. Alternatively, work on getting a third party package onto the Mac where their is obviously an opportunity.