Skipness,
I also think that the "next" UK base for Ryanair will be Gatwick. When have Ryanair ever allowed Lingus to get comfortable in a particular market. Since Lingus started Gatwick hub, we have seen Ryanair show more interest to Gatwick launch Alicante, Barcelona, Madrid, Marseille. I think Weeze came before EI announced Gatwick, but it soon went too.
It also seems that most other main Low Cost carriers have bases at Gatwick, easy, Flybe, Aer Lingus...Only seems logical that Ryanair would want in on that too.