Agree about Encirca's bulk functionality, up to 500 domains on 1 page overview, and non auto renew default setting. When I started regging .pros, I bought a list of the top 17,500 keywords with PPC and Overture stats, sorted the top 2,500, then cranked through the bulk WHOIS check to identify which were still available to register.
I added Snowmobile.pro and Jetski.pro for $85 each during the week. I think .pros like this are dark horses, they have little reseller value but Pro branding is popular in both product categories. I use Google uniques for the keyword and Pro divided by Google uniques for the keyword to benchmark the level of Pro branding and Pro association and each one of these scores about 20%.
In simple terms, the word Pro appears on 1 in 5 Google indexed pages that also include the words Snowmobile or Jetski. The underlying reason for the association is Snowmobile and Jetski are sports, hobbies, and technical products, all 3 of which work well with Pro branding.
If .pro does become more mainstream, Pro branding potential and not just conventional keyword KPI's will drive sales. For example, MJS sold Antique.pro, Book.pro and Lingerie.pro between $1,000-$3,000, excellent keywords but not necessarily suited to Pro branding, but added Tennis.pro on Snapnames, and hand regged Raft.pro in December 2008, both of which are suited to Pro branding.
Where .pros have sold for more than they should on paper, for example Chef.pro at $3,650 and Freelance.pro at $5,440, Pro branding potential has been key. Where you get anomalies, for example Book.pro selling for $3,000 but eBook.pro selling for $3,900, there is a Pro branding explanation. On the ratio I used above for assessing the Pro branding potential of Snowmobile and Jetski, Book scores about 10% but eBook scores 20%. i.e. when you "tech up" Book by putting an "e" in front of it, it becomes more suitable for Pro Branding, consistent with the higher level of Pro branding in the electronic hardware and computer software sectors.