In some cases, manufacturers are seeking additional certifications, such as Vista/WHQL and Intel Centrino, which is taking additional time. Since manufacturers prefer to minimize releases of new firmware and drivers due to the testing and support issues they bring, companies are waiting until all certifications are complete before posting the software for download. And even when new drivers and firmware are available, it will take a few months until updated and Draft 2.0 compliant products make it into the retail channels.
Since it is our policy to test products only with publicly-released drivers and firmware, this delay is why you haven't seen more reviews of draft 11n products on SmallNetBuilder. We have had products from Linksys and D-Link sitting in the lab ready to be tested for almost a month now, waiting for Draft 2.0 firmware and drivers to be released.