I think part of the problem is that the various blogs -- sadly including this one to some extent -- don't do a good job beyond reviewing (1) the heavies (navigation apps), and (2) games. For example, I purchased a GREAT app to review the security cameras around our house. It's amazing, and incredibly intuitive. The user reviews, as always, are so so -- people upset that (1) it costs more than $1.99 (hey, don't buy it, but it's worth $24.95), and (2) can't figure out how to configure it (which the developer will help you with). I've never seen this app reviewed by anybody.
It's hard to blame iPhone-specific blogs to some extent, since these are more specialized apps that are beyond the domain of such blogs. But the problem is that they're not being reviewed by, say, domain-specific blogs (security camera blogs, for instance).
I think one way Apple can alleviate this problem is to have an affiliate program. Sellers can choose to sign up affiliates, who can then market apps on their web sites and get a percentage (app developer determined) of the proceeds. In the example app I've mentioned, there are a lot of security camera vendors who could easily put this thing on their web site, make a few extra bucks off the sale of the app, and then provide support (for instance) of setting up cameras that they sell if you buy the app from them.