Looks like it evaporated--bummer. There is a post on Karl Soule's blog about the (temporary?) demise of Ultra, at least in CS4: http://blogs.adobe.com/VideoRoad/2008/12/help_for_ultra_1_and_2_custome.html
I also want to reiterate that the ULTRA technology is NOT DEAD. The vector keying is alive inside of Premiere Elements 7 and Visual Communicator 3, and there's still development going on for the professional CS tools. (It just didn't make it for CS4.) As a public company, there are legal reasons why I can't share all the details, but there are good things coming.
To me, that reads like a not-very-veiled indication that Ultra will, at some point in the future, work its way back into the Suite. If you look at OnLocation as an example, between CS3 and CS4 it became a whole new application, and gained dual-platform support. It seems logical that in Adobe's way of Borg-like assimilation, Ultra won't resurface as its own application until it gets a total dressing down like OnLo did. Makes sense, I guess, though I'm sure it causes headaches for operations like yours that build it into a workflow.
The problem is that the marketing of Adobe products is so mysterious in many ways, that most of us don't understand it at all.
In CS2 we had Audition, which was taken out in CS3 to be replaced by the crippled SoundBooth. Then in CS4 we got back the capability to 'Edit in Audition' but one needed a separate purchase of Audition CS3, which was never upgraded to CS4 status.
In CS3 we had Ultra which was excluded from CS4.
In the old days the Serious Magic forum was alive and well and a good source of information. After Adobe acquired Serious Magic we lost all the valuable info on the SM forum, we lost the valuable tutorials, we never got the MSL4 that was planned before the take over, the sale of MSL 2 and 3 was stopped.
There are still a number of Serious Magicians working at Adobe (Karl Soulé on the Ultra part, Mark Mapes on the OnLocation part, and maybe others) but valuable contributors like Dennis Sladek and the like have vanished into oblivion, at least for us here. That is a pity.
I hope Adobe gets their act together, and I know that people like Karl and Mark would welcome a new infusion of live into Ultra.
It's good to hear that there is encouraging news and optimism. One of the things I like about Ultra besides the clean keys is the ability to export from Ultra as a 32 bit keyed source. I occasionally use the Ultra-supplied backgrounds and sets, but they mainly serve as a quick way to check the quality of the keying in front of a variety of different colors and patterns. The 32 bit clips exported from Ultra are a hefty file size and take some cpu horsepower to play on the timeline in Premiere, but this 32 bit keyed source option offers great flexibility in editing. If a client doesn't like my choice of backgrounds, changing them out is a fast and simple process.
"It seems logical that in Adobe's way of Borg-like assimilation, Ultra won't resurface as its own application until it gets a total dressing down like OnLo did."
Ah yes, the Borg. My wife and I were hooked on the "Next Generation" back in the 80's. I met Patrick Stewart and spoke with him at length back when he played Captain Picard. He seemed surprised that I thought Star Trek the Next Generation was a great TV show. He was probably so burned out from filming and trying to remember his lines, that he never had a chance to actually watch the show E.G. "Galaxy Quest". Anyway, only Patrick Stewart could say a hokey line like "I am Locutis of Borg" and have it come across convincingly.
I do think that Adobe has assimilated some great companies/products though.