Oh my my my, where do I start. Production houses, news facilities, freelance professionals. I talk to these people on a daily and weekly basis. They're all buying or just bought new gear. Not a whisper of "Oh I feel like I'm getting screwed by Apple, I hope they update the Mac Pro soon". No way. They're all "We need what we need now, we don't care about an update because it's not out NOW." You're idea that Mac Pro users are "forced" into a position is ridiculous. The target market for Mac Pros aren't FORCED into anything. You're projecting your own fear, frustration, and arrogance onto the professional market for which you've not demonstrated any credible representation for.
And as far as MacBook Pros being updated, more and more CONSUMERS are buying those because more and more CONSUMERS want dedicated graphics cards, bigger screens, etc. I'd say if ANYTHING, notebook buyers are getting "forced" into buying something. MacBook Pros are being updated more often because of newer technology and increased demand. MBPs are outselling Mac Pros by a HUGE margin and thus require more refreshening and attention. Mac Pros simply don't need that kind of attention.
Is there new tech out there that it can use? Sure. Is Apple feeling pressure from it's target market to update it? No. Will they? Of course. Back in the G5 days, there was incredible pressure to update the Pro desktops. But now with 4-8 Xeon processors, a 4TB internal HDD ceiling, a 16GB RAM ceiling, and 4 PCI-e slots, we're set for a while thanks.
And yes, working inside the mothership DOES give me more insight than you. And yes, working among and inside the target market (high end post production, news, freelance) for the product in question DOES give me more insight.
That being said, if Steve mentions a Mac Pro update at the keynote, I'd be happy to take all my claims back and admit defeat (I'm sure you'd be happy to rub it in my face), but I'd say it's unlikely to get a note at MWSF's keynote.
P.S. Dealing with Apple users and customers for a long time, I've found that about 97% of people don't care when the products are going to be updated. They don't even realize that there could be an update in the next year, nor do they care. They buy when they need it. So if you're WAITING on an update, it's simply because you HAVE to have the "LOOK AT ME LOOK AT ME" latest greatest thing available. The updates the Mac Pro is going to get will NOT have a life-altering or earth shattering impact on your user experience. Trust me.