UDK is not UE3. AAA games are made with UE3, casual games are made with UDK. So your first question should be: which is my target company type? Nothing is going to get big paying 25% of its revenue in licensing, there are no examples yet, and I very much doubt there will be outside the occasional lucky single-developper AppStore hit (do not confuse with the huge success list of UE3, which has a different licensing scheme, but will likely require much more C++ knowledge if you're hired to work with it).
C++ knwoledge is universal and can get you a job working on the F35, for a global company for consumer electronics, in a hospital... UDK is getting you nowhere at all, except where it excels, which is a niche however interesting it may be for you at this time in your life. Are you that sure you want that bad to work for a (likely small) game company forever, when the game industry has changed so much in so little time?
Finally, C++ has been around for a long time, is there to stay under different incarnations (you'll be a lot more efficient learning C# from C++ than from UDK script), whereas UDK script is very very good at one thing: language support for asynchronous events. Essential in some environments, but talk about a hard-to-sell skill!