The main differences have been pointed out:
Capacitive:
- hard surface
- faster response to input(?)
- higher cost per pixel for a given screen size
- less accuracy (end of finger is smallest object that can be "hit"?)
- multi touch

Allows you to assign different "meaning" to one and two finger swipes etc. NOTE so far this has only really been seen on Apples new mouse!

- Danger of a "big" sheet of glass (cracking, chipping etc)


Resistive:
- lower cost per pixel for a given screen size
- anything can be used for input
- accuracy

This combined with the higher resolution screens means that you don't need to zoom as much.

- worry of scratches

minor worry for me, only after a year of HARD stylus use did my old palm pilot start to show scratches in the "grafitti" area, but as most of the time I'm using my finger, or the keyboard, I think it will last OK.
Anyone with an N8x0 care to comment on durability of the screen?

I think much of this argument has been caused by the iPhone. What was revolutionary was the UI was better and faster, and it seems the tech press confused this with the switch to capacitive.
Also, I think this was the first mass-market device with a capacitive screen that did not cost stupid amounts of money.

I had a chance the other day to have a short play with a Nokia X6 (3.2“, capacitive, 360 x 640) and at the same time(on the same display was an N97 mini (3.2“, resistive, 360 x 640).
From that, I could not find much to recommend one over the other (reaction time, responsiveness etc) all were about the same! [Disclaimer: this was a 5-10 minute semi-random stabing at icons play, not a proper scientific test, in Verkkokauppa.com's Helsinki Store]

for comparison of screen resolutions, the iPhone has a 480 x 320 screen (i.e half hight VGA), and the N900 wins with a 800 x 480 one.
So total Pixel counts are:
iPhone - 153600
S60 5th - 230400
N900 - 384000