[tomsem]

Since you don't seem to be in any rush, I would wait awhile longer, at least until the first software update arrives (and ideally, wait until Kindle Touch gets an update so you know how software features will compare). This will also allow more time for production issues to get worked out, increasing the likelihood that you'll get a 'good' one. Then order one, try it out, and return if it doesn't meet your expectations.

In terms of software, Paperwhite is very similar to Kindle Touch, and I expect that KT will get even more similar when it gets an expected update (to add Whispersync for Voice to the audible app, to add fixed-layout KF8 support, maybe 'fix' the line spacing kf8 bug, and possibly add some of the Paperwhite UI refinements). But for now, this is what is new:
- home screen is redesigned, with optional Cover View, and easier access to Cloud (Archived Items). The latter now has 'Recent' sort option.
- reading options include 'x minutes left in chapter'/'x minutes left in book' status, and more logical grouping of options at the top of the screen where you tap to bring up menus and options. There are 6 typefaces instead of just 3 in the case of Kindle Touch.
- Parental controls have been added
- line spacing seems the same with both kf8 and mobi. Paperwhite supports all of KF8 (except for embedded video/audio, obviously)
- they have removed the 'chapter navigation' swipe gesture (still works for article navigation in periodicals)
- they have buried the wireless toggle in the Settings menu, annoying if you like to manage your Kindle's power consumption closely

Hardware:
- the screen, obviously. higher resolution, built in light. There are 'shadows' at the bottom of the screen where the LEDs are but I barely notice them. It's really gorgeous in well lit environments (yes, with the light turned up). In poorly lit environments, most people will find it better than using a reading light. For me, it is better than KT about 85% of the time, and 15% where it is slightly worse due to some off-white color that creeps in when light is iffy (on the PW I have right now). In complete darkness, I prefer PW as I turn the screen light to at most '2' and don't see colors then. YMWV.
- capacitative touch. more responsive, does not have the thick dust-and-hair-and-crumb catching bezel found on KT, slightly thinner overall, can be operated in zip-lock bag for beach and bathtub protection.
- they are advertising improved battery time though as always that depends on your usage patterns. I leave wireless on all the time and it doesn't seem to go as long as my KT does with similar usage (both are 3G models).
- no Home button. Takes 2 taps to get Home. But maybe that makes it more 'immersive' (ahem).
- no speakers, no TTS, no MP3/audiobook player.

Overall, I like it much better, even with its negatives. But given what I paid for it ($180+tax), I can't say unequivocally it is 'worth it', considering my KT is perfectly fine. It was new, and I wanted one.