Looks great, I built a similar too but shuttered it after a couple years. I was able to get a few good domains in 2008 but once pre-emptive bidding on expired domain services like snapnames came around, it was much less useful.
I recommend adding a feature to filter domains that contain numbers/hyphens.
I see some decent potential here for domain typos. Domain parkers would love to be able to locate some high volume unregistered domains. It doesn't look like you have a page just for the most common typo'd domains across all domains. Is that a pro feature? If not, it should be.
I hope people don't see this and think it was the same submission that was put up when Fred Wilson first published his piece. This is a great comment to that post and offers more helpful information than the original post.
ummmm, huh? They've always compared OSX (which only run on a handful of Apple exclusive devices) and windows OSes in the exact same way. No market share report I've ever seen phrases it as "iphone vs android OS". It is always iOS phones vs Android OS phones or iOS tablets vs android tablets. I don't understand what "truth" is being uncovered here.
If you are worried about your PageRank number, your priorities are off. Be worried about your actual search traffic. If that has not dropped off, there is not cause for concern.
As far as advice goes, I'll stick with the default white hat advice: Improve your search traffic by building as much good original content you can and form relationships with other quality relevant sites that lead to backlinks.
I recommend adding a feature to filter domains that contain numbers/hyphens.