(*See my comments on the Kobo thread)
Wife has Kindle (paid R1K a year ago) with special offers (works in SA) and got my daughter the Kobo (RRP R1K).
Kindle:
* No touch screen which is great for just reading in bed at night as its easy to accidently touch the screen to flip the page when shifting into a more comfortable position. Uses large buttons on side (duplicated on both side).
* Buying books on Kindle is magic, easy peasy and very fast.
* Has very good fonts
* Less blot
Kobo:
* Has SD card slot (both have 1GB internal storage)
* Touch screen
* Has social integration (link your facebook to join a book club)
* Books are generally a few rand cheap
* Bookstore library limited
* Way cooler user interface with lots of eye-candy
* Can customize appearance and wide selection of fonts.
Both:
* They both use the same screen
* Both same form factor
* Both same charger
* Calibre

works on both
I'm glad I got my daughter the Kobo instead of the Kindle, but then I'm glad I got the wife the Kindle and not the Kobo. As for the issue of loading books, use Calibre. Allows me to convert any existing format to another and great for managing your devices. So you can buy books on Amazon and convert them to the Kobo, or get books from Kalahari and upload them to both devices.