The resolution vs viewing distance chart should weigh heavily on your decision. I have a 52" 1080p panel with 8-9' viewing distance hooked up to a laptop among other things. For me, (with normal vision), default fonts/pitches are perfectly readable with no aliasing (if not a bit small) from my seating position. Moving closer, I can start to see individual pixels, while further away, it is too hard to read. This tells me that I have reached the balance between resolution and viewing distance optimal for my eyes' capability to resolve detail.
I'd advise against holding out for >1080p panels since there isn't any source material (other than self-generated or computer-based) available. Blu-ray is the best commonly available source / equipment with a native resolution of 1080p, so that is where it's at for now.
BTW, I'm pretty certain that displays that only accept 1080i are still able to render 1080p/24 with inverse telecine, although you may notice judder. FWIW, 1080p/120 hz panels have fallen in price a great deal in the last year, if they aren't yet cheap enough for you, why not wait a bit longer? Then you'll have 1080p with ability to display 24 hz material with no judder, i.e. 5:5 pulldown. Provided, of course, that your tv's manufacturer implements a true 5:5 pulldown, which is the case for Samsung, Sony, and possibly others.
On the plasma side, you'd look for 72 hz panels with 3:3 pulldown to properly display 1080p/24 source material (e.g. most Hollywood films on Blu-ray or HD DVD). Not certain if that is what they call it, as I am an LCD guy (fits my need much better than plasma).
Edit: Disclaimer: I have a Samsung LNT5271F LCD, and am very happy with it.