Ebooks will take off eventually, but they don't offer any major advantages over dead-tree books at the moment. And for each advantage there's also a disadvantage.
Now if they were half the price, that might not matter. Or if paperbacks were sold with a redemption code for the eBook thrown in for free they might be able to slowly slide into greater use.
But at the moment they're just not viable. £200 is a lot. I might consider though if it did what my iPod did - let me carry my entire book collection about with me. But it doesn't. In fact I'd have to re-buy every book I want to read on it. Would the iPod ever have taken off if it'd only play albums you bought off iTunes? And they were the same price as the CDs. And you'd have to rebuy all the old ones. No chance.
The convenience and ease of use of an eBook reader really appeals to me. But I have 100s of unread books. If I can't read those on it it's no use whatsoever.