I know there are many who complain about things like the inability to copy and paste text and so forth, but I've not found that to be much of an issue.
In general I'm the type of guy who reads books but doesn't lend them out. Not that I wouldn't, mind you, but it just doesn't happen that much. And since my local Borders - my de facto place for getting computer/tech books - closed last months, I'm happier than ever to be a Kindle user. (Even though I get the irony in this).
Physical books won't go away and ebooks are still evolving. I look forward to what the future of reading holds.