For me low cost airline near to be closed are Skyeurope and Vueling due to financial problem and price war.
I think
Vueling will merge with
Click Air (previously rumored), but no idea as to what form this (new) airline would take.
Sky Europe are defo in bad form, if they don't make this summer work, then it'll be their last summer ever.
But before all others, I think
Centralwings will be the first to fold.
Ryanair could take over most of Central's interesting routes without even setting up a Polish base. Wizz would also mop of a few of them up for sure. Maybe even Norwegian would be tempted to embark on a second Polish invasion, and reinforce themselves further in the region.
As for Sky Europe's routes, Ryanair are already present in Bratislava, and a Bratislava base wouldn't be such a bad idea, especially in the wake of Sky Europe when the airport would be desperate to replace lost routes / pax / jobs. Ryanair have had on and off negotiations with Vienna, maybe it won't be too long before we see them there.
Sky Europe disappearing off the Prague radar would probably encourage other airlines to look closer at this airport: Easyjet, Ryanair, A LCC version of Czech, Aer Lingus, Wizz, Air Berlin, German Wings, Air One etc...