Looks great, but I'm happy with what I have now so I'm not too pushed about spending money on a service. I'm also old enough to worry about trusting a site to hang around for 10 years with my data. (and by old enough, read: stuck in my ways enough) Must look into the migration effort though. And browser addon support. Its definitely a sweet looking service.
If you go for the premium service, a bargain $25 a month you get the ability to have it scrape and download every site you bookmark. So even if the site you bookmarked goes down, you retain the content.
Pinboard also has good APIs so you can backup your data. No lock-in.
