I personally wouldn't be so worried. A lot of people are disillusioned with the EU and voting UKIP is a protest vote which represents that, rightly or wrongly, if you don't agree with the EU UKIP are the only party that probably feels like actually supports your own views, it's easy to vote on one issue.
If anything, it is a good thing it is a General Election next year because this is a damn good warning to the other parties, people WILL go out and vote if they are getting pissed off and there's an option that is much more realistic than the Green Party and BNP, too long the parties have been able blend in to a boring shade of grey, all being very similar in their actions, now they will have to fight to get people to vote for them.
That's just my opinion, no doubt people will disagree, but I'm personally not worried, I think it's all being a bit over played but hopefully that too will scare people to the polls, because I wonder how many of these people that complain about the idea of UKIP did actually go out and vote (not talking about people here).