Wizz Air started flying daily to Katowice from Luton at the end of May and this is due to go twice daily from the end of June.
At the same time Wizz Air will launch a daily services from Budapest to Luton on the 26th June and this again goes twice daily from the middle of July.
Hapag Lloyd Express also flys to Katowice from Stuttgart and Cologne.
I don't have the news article to hand, but when Ryanair announced there annual results a few weeks ago, Michael O'Leary said he had no immediately plans to launch routes in Eastern Europe and made some quite controversal comments. Saying how people in Western Europe had higher levels of disposable income and how people wanted to visit historical cities of interest and not ex-communist concrete jungle cities (or someting along thise lines!).
easyJet are already operating flights to Budapest from Luton and soon from Gatwick and Ljubljana from Stansted. So I think it is only a matter of time before easyHet operate flights to Latvia, Estonia, Lithuania and Poland.