By now, you've probably heard that Borders Bookstore is coming out with their own reader, the Kobo eReader. It's already been introduced in Canada (by KoboBooks, a Borders subsidiary) and is available to pre-order in the US ($149) and Australia ($199 AU; from the Kobo Global website). Delivery should be just in time for Father's Day (current delivery date is June 17). I was talking to the manager at our local store last weekend and he said they will be putting in a download station in place of most or all of the customer service desk, so that customers can purchase ebooks in the store and load them onto their readers. That'll eliminate the need for a computer and for much technical know-how on the part of those who get one (although you can still do your own backups and transfers at home, using either bluetooth or (I'll presume) USB).
So far, there isn't a Borders eBook Store, but it is being worked upon (and scheduled to open in June). There are quite a few differences with the readers available already - a quilted back should make it quite a bit easier to hold, but the big single button on the front seems to perform most of the chores that several keys or buttons are needed for with others. The desktop app is preloaded on the device - hook it to your computer and it will install, eliminating the requirement to find the software yourself (which I've run into with other readers). You get five type sizes and a choice of serif or sans serif fonts; there are several options for sorting books, but the only "collection" appears to be a way to tag "books I'm currently reading". The screen is a now-standard 6" eInk display and the unit is one of the lighter ones out there, at 8 ounces. Capacity-wise, though, you get one gigabyte of memory and an SD slot (but not an SDHC slot) that essentially means an unlimited capacity. So far, the formats supported at ePUB, PDF, and Adobe DRM (which should mean PDF and EPUB); I don't see any support for DOC, TXT or some of the other formats that many other readers support, but all of those are easily converted to ePUB by an application like Calibre.
Once you buy any books at Borders, one big question is always which devices can be used to read them. So far, they have announced free eBook Apps for the Mac, PC, Blackberry, Android, iPhone, and iPad. Books can be synced among devices (including via Bluetooth directly from the Reader to a phone). It looks like you'll be able to buy books from other bookstores, as well, so long as they "support Reader® Mobile Technology from Adobe." The only downside to their bookstore, that I see so far, is that they claim you'll need to use the Borders eBook Desktop App to search or browse for books (which you will presumably also be able to do in stores). I'd much rather use a web based store and download books to my computer for manual transfers. So far, it appears that only PDF's can be manually loaded, while EPUBs will require the desktop application.
I'm not sure I'd like it for a primary reader, but as a secondary reader (for those DRM'd epubs you keep picking up, to read books from Penguin that you can't get for Kindle, currently, or for additional people in the household, for example), it looks like a very good deal (especially at $100 or so less than the other readers that are the same size).