Or they could go to a 13.3 @ 1280*1024. (it'd be possible: there are 1400x1050 14.1" panels, so cutting that panel just a touch smaller would put it in the ball park.
Of course this could only happen if the TiBook went to about the 1440x960 to 1620x1080 range of resolution. Assuming the fab technologies are generally standard and the glass is prepped to be cut at different sizes, I think that a TiBook would have to get a resolution of 1575x1050, if they take a 14" panel (which is the same height as Ti's 15.2) and cut it a little wider.
I don't think anybody out there makes glass that would yield 1440x960 in Ti's exact dimensions. Which leads me to another, not so optimistic, thought. Ti's resolution may stay exactly as it is for quite awhile. The non standard aspect ratio makes it hard to source acceptable glass. A really high resolution probably wouldn't run that well on a mere 16MB of VRAM. Ti would need at least 32. Apple tends to stick with a video chipset for a long time, so don't expect a change. And, ultimately, a more manageable res where the dots are not too small, and the Vid system overhead isn't too great, may not be available. Pessimist Matsu sits down.
What would we get if Apple cut the iBook glass in TiBook dimensions??? I sure hope they do it.