Hi Alimha,
Bear in mind that I am no expert, but just from my own experience as an investor trying to sell my apartrments in JVS, I found it extremely difficult. The feedback I got from agents was that the delays associated with JVS were putting people off and I couldn't agree more. I purchased my studios in July 2006 and held onto them for over 2 years without any movement at all in the project. Further more, the majority of JVS projects seem to be getting pushed back even further from their anticipated completion dates and to this date, not many JVS projects have even started construction.
Secondly, you have to remember that JVS appears to be full of small-medium time developers, who do not have much experience of developing in Dubai. With projects being delayed (apparently because of legislation and plot handover delays by master developer, Nakheel),these developers are struggling with the rise in cost of construction materials and rumour has it that some developers are stalling as they cannot afford to continue with the project due to the rise in cost (therefore looking to sell on their plots to someone else).
Thirdly, there seems to be alot of bad press with some JVS projects (e.g. Jehaan/Aspire) and bad publicity never did anyone any good.
Regarding your question about long-term interest, who knows, but if JVS does eventually kick-off and the whole community get's completed, sure, prices will go up. But looking at the number of projects being delayed in JVS, I can't see things moving too fast or JVS being anywhere near completed before another 5 years.
JVS has a decent location, although if you have been to visit Dubai, you'll find that traffic congestion is poor and infrastructure is not great by any means.
The question is do you want to hold on for an infinite time, without knowing what the future holds for JVS or take your money back and get out. I'm definitely glad I took the second option and wouldn't touch Dubai again until things are a lot more stable with sensible laws and regulations.
Mohamed.