I found some, but frankly, I was looking more for a relaxing vacation by myself to anywhere warm to escape the early cold and snow in NY, and meeting other singles wasn't really high on my priority list. The weather cooperated fully with my plans!
The Vision of the Seas wasn't anywhere near full, but it had a good mix of ages, and I even recognized some casino personnel from a repositioning cruise I took on the Nordic Empress a year and a half ago. All in all, a very nice experience -- and those inside singles that look so cramped for two feel like luxury suites when there's nobody else in the room! (Plus, you get to eat BOTH of the chocolates yourself...)