Hi Nina,
First of all there are a lot of hoaxes about the project and people like to talk negative about the Pearl(maybe jealousy!). So, we shouldn't believe and act according to those hoaxes. On the other hand there is a certain fact that the project is delayed a lot... So, before making any decision I think you should consult with UDC officials and your developer first.
After my investigations, I am convinced that the main reason of delays are not because of main developer(UDC)or any governmental issue, instead the problem is most probably with your developer.
Maybe you know, before the handover, the developers are needed to pay fees, give commitments v.s. to the main developer. The issue of delay could be caused by those things. But of course they will never say that the delay is due to themself, instead blame master developer. Look at what happened with the First Qatar. The developer is charging the complete connection fees to the owners. I never ever heard such thing in anywhere in the world!

So far I never heard of anybody cancel SPA so far but a lot of people thinking and discussing this option.

Personally I am not at that stage yet because I want to live in there and believe that soon this misery will end.
Good luck!