http://www.techweb.com/encyclopedia/defineterm.jhtml?term=mainframe

That looks about right.
NASA is moving some of their infrastructure to cloud computing. As is AT&T. Most of it in both cases is spread across multiple VARs. Even Lockheed is doing this for computationally intensive tasks because it’s a heck of a lot cheaper. Send the data to them on a small pipe, let them crunch it, send the result back on a small pipe. If you own a bunch of servers, you can lease them out so they are always in use. Meanwhile the customer doesn’t have to maintain a specialized environment and keep that ridiculously expensive hardware on the books. It’s a win-win. Depreciation on that kind of equipment is a real bugger.

As stated in my previous comment: “…mainframe computing will become obsolete in all but a handful of very specialized areas…” I never said it was going away entirely. Even if no one hosts their own mainframe data center, the I/O throughput has to come from somewhere…

And I don’t expect the NSA, Mossad or similar agencies to ever give up their precious mainframes. The data they work on is considered too sensitive to allow that work to be outsourced.

I don’t think the mainframe will ever die. I do expect it’s role will change. Technology has that cycle. Expand and decentralize, then the bubble pops and everyone rushes to consolidate and centralize. Decentralize, centralize, repeat.

No matter how you look at it, Ubuntu (my favorite OS)currently has no business in mainframe computing and they seem rather glad of it. I’ve seen Ubuntu on a POWER-based mainframe, but it wouldn’t be my first choice…actually I don’t think I’d even consider it.

I think it’s great Canonical is staying out of the mainframe arena. As cloud computing becomes more commonplace, mainframe computing will become obsolete in all but a handful of very specialized areas and as already mentioned, SuSE and RedHat have that very well covered.