Canon Dilemma

I have a dilemma.

Two actually.

I. Autofocus in my 20D stopped working last week, and after diagnosing it with Canon, they recommended sending it in. I did, along with a note that the pop-up flash occasionally won't pop-up. Today I received notification from Canon that they want $300 to repair the camera (it's well over a year out of warranty).

So this isn't really much of a dilemma. While some may question spending $300 on fixing a 20D (HamWithCam already has), it's worth it to me. It's been of great use and I'll continue to use it (if the shutter doesn't break next -- I'm sure it's well past it's 100,000 cycle life. Several times over, most likely).

I've wanted a second body for a long time, and have been thinking about it much more since I've been without my SLR for a week.
(in the mean time, I've gotten a few good shots with some of my point and shoots)

Hence the next dilemma.

II. XSi (450D), 40D, or 5D?

Let me preface this with stating that I've wanted a full-frame sensor (i.e. 5D) for nearly a year, and have been holding off for the past six months waiting (hoping) that Canon will announce a 5D mk II (or maybe even a 7D). After all, they've revamped everything else in the product line.

Here are the things I'm waiting for in a revised 5D:

• Higher ISO
• Highlight priority
• Dust vibrator (you know, in front of the sensor, I change lenses a lot)
• Digic III (because III is better than II?)

So here are my real questions:

Which of the above three has better ISO with less noise?

Is ISO 3200 on a 5D better than ISO 3200 on a 40D?

Even if that's the case, I still want full frame (think wide angle).

What do you think? Will Canon ever update the 5D?