I've had a del.icio.us account since the beginning in 2003 and migrated to Pinboard last year. It's a worthy replacement and everything Delicious should have been, with something approximating the UX from the older service. And Maciej and pvg are very responsive on Twitter.
I'll second that. I've been super happy with pinboard. They personally helped me track down some technical problems I had importing my delicious, and haven't looked back.
