So same target, different approach that you'd see as less appropriate than DarkStar?
Same target, VERY different approach. This is similar to the fantastic failure of IBM/Butterfly.Net GRID "experiment" done 3+ years ago. Here is the fundamental difference between the approach that IBM and Sun are taking in the space. IBM's answer to online game technologies is to provide tools that a game developer can use to create their own build a server solution. None of what IBM offers actually helps game developers understand HOW to build such a beast. For that, you must rely upon IBM's "services" division. The approach we took with Darkstar is pretty much the opposite: present a highly scalable, fault tolerant, multi threaded system as a mono-threaded server accessible through APIs. Our goal is to provide a solution, IBM's is a jumble of tools.
Take a look at how IBM breaks down their game server architecture:
Notice anything? Completely hardwalled architecture. No scaling across the entirety of the service, no resource allocation between their "zones", etc. On top of that, the new IBM "Gameframe" solution is a mix of mainframe and Cell based servers. How proprietary is THAT?!? Consider that the cheapest IBM mainframe, the z9, starts at $100,000 and no pricing on those Cell blades, and you are talking about Sony/Blizzard prices infrastructures. With Darkstar, you can start on your single $500 dev box and scale up from there.
So again, same target, and IBM is using the same old approach that the industry is trying to move off of. Not only do I believe it's less appropriate, I believe they are moving backwards.
EDIT: Another example of more exotic hardware being used to smooth out implementation issues is the solution for EVE-Online. In order to get to the 30,000 players per shard number that they claim, they had to install military grade Solid State Disks that can handle 400,000+ random I/O per second. An this is in a game that is instanced. Again, throwing more hardware at a software problem is best left for last generation thought of online game technologies and for Vista (oooohhhhh!!!!).