I'm not going to comment on the quality of The Pearl.
And property 'value' means different things to different people.

However, when you look at what a nightmare the Dubai property market has become, who wouldn't get cold feet?

Aside from the huge losses and extended delays that buys are experiencing, there are also the practical uncertainties with regard to the amount that will be levied for maintenance, the connection of utilities, and most importantly, the issuance of visas.

The UAE looks set to change property ownership laws such that an owner will get a SIX MONTH, RENEWABLE RP upon purchase:
http://www.khaleejtimes.com/DisplayArticle08.asp?xfile=data/theuae/2009/...

For me, that is a totally unattractive proposition, made worse by the knowledge that the visa law could change again at anytime.

I would have a hard time believing that such a thing would be unlikely or impossible in Qatar.