ukip have done several things
they have caused more policy changes in the tory party than the libdems
they have had all parties running about like headless chickens
the parties will now know they have to listen more to the chattering classes
but thats it they will now disappear into history like other protest parties with little or no further influence
I agree that they have already achieved a great deal without getting a single seat in parliament (although they have now, of course), and I for one am grateful for that.
As for whether they will now disappear, I suggest we wait and see. Realistically, I doubt that they would obtain an outright majority although I still maintain that this is possible. After all, didn't they just do that in the EU elections?
Another encouraging thing is that they now appear to have effectively replaced the Limp Dems, at least where polls and by-elections are concerned. Perhaps it is the Limp Dems that will disappear into obscurity, and UKIP become the 'third party'.
One possibility is that they will acquire enough seats in parliament to have an influence if the Conservatives and Labour are fairly evenly matched. Nigel Farage has stated that he will not form a coalition with the Conservatives, but that hopefully he can influence decisions without forming part of a coalition. I think he has already done this, hasn't he?
The main thing is that more and more people are of the opinion that the three main parties (if we include the LDs in that description) are just not listening to what people want, and they want someone who will. Of course, different people want different things, but one very common concern now is immigration and the current big influx that is beginning to swamp the country is from EU countries. The EU mandarins have slapped David Cameron in the face and told him that they won't give an inch, so it's unlikely he'll solve the problem. Labour (and the Liberals) are adamant that they want us to stay in whatever, so there appears to be only one answer to immigration: UKIP.
We shall see.