It was heavily rumoured after blackfish that they were interested in purchasing some of the Sea World parks. It's also not unheard of in the companies more recent history, with the purchase & re-development of Cypress Gardens into a Legoland. Considering the company is truly a global powerhouse, I'd be surprised if they're talking exclusively about the UK market here.
For a while it was suggested that Merlin saw their resorts more as burdens (with the exception of Legoland), as they managed to pick up a trend of cheaply developing their midway attractions, like the Dungeons, Madame Tussauds etc. Happy to hear if this era of their portfolio development is coming to an end, I hope this means they'll pay more care and attention to their existing portfolio in terms of longevity of investments and general upkeep and can carry that attitude on into any new investments they make (although I know that'll only happen when pigs start flying)...