I wound up selling my eBookwise because it's huge and weighs a ton

I have a Sony now and much prefer it. To answer your questions...
1) Sort of. If you are willing to strip the DRM, you'll get an HTML file which you can easily use with the eBookwise, or with any other device you have. But you'll need to be prepared to do a little fiddling. I did not know of this when I had my eBookwise so I only read multiformat Fictionwise books on it.
2) I am going to say no, for two reasons. First, the trend seems to be eink and the eBookwise is LCD. So it won't get much lighter, and it won't get much fancier. Also, the eBookwise bookstore is crapola. Sorry, but it is. Nearly all the books are 'protected' IMP files, and by 'protected' this means you can only read it on the actual device to buy it on. So, if you have an eBookwise, buy a book in this format, and then your reader breaks or gets stolen or whatever, and you buy another device FROM THEM, you can't re-download it. This is the most restrictive DRM in the biz and imho is a losing proposition. Other bookstores which have devices associated with them sell in more open formats. Amazon has a proprietary format but you can read it on more than one device, and Sony is selling protected ePub which can be read on numerous devices.
Just my opinion

I sold mine to a good home where the person already had an eBookwise, knew what he was in for, and was techie enough to much around with other formats. I would not personaly buy an eBookwise again.