I agree, although I feel there is a large barrier to entry to entering the review business since you need to buy a lot of expensive things to review them.
Not always. I have a friend who runs a pretty popular Android blog, routinely mentions that at times, it's as easy as asking for a review product and it's yours.
Check out my profile and shoot me an email, I'd love to maybe give this a shot.
An excellent idea and I'm sure there's definitely a gap for it, as long as you're a decent and enthusiastic reviewer and writer.