Looks very nice, but how are you offsetting the cost of operations? I only ask, because the work involved moving names from one place to another takes time from other work and I'd like to know the site may be around a while before committing to it.
I run many online ventures in the uk market. Ukbackorder, ukdroplists, hotel sites, etc. I have currently over 100 servers and vps. It runs itself - the cost of operation is virtually zero. It is what it is. Feel free to use it or don't - I have all my domains on it so it will be around as least as long long as I am. Also it takes only a few minutes to add thousands of domains so if you can batch change your nameservers the time taken for you is going to be less than an hour.
But to give you an idea of the massive amount of work involved... I batch changed 2000 uk domains nameservers which took about 2 minutes. I then parked them all which took about 2 mins. 1 minute to reupload some that hadn't propagated nameservers yet. Not really a big issue