We have some replies from Twitter:
Yep the mono rail runs from the trunk of the Palm Jumeirah to the Atlantis Hotel and back.
presch said: It starts from the trunk of the Palm Jumeirah and stops at the Atlantis Hotel. In-between stops still closed.
presch said: oh forgot to tell you US$4 for one-way trip and $7 for two-way...and I meant 'stops' in-between are still closed. about 8 years ago
Monorail up and running but only from Palms to mainland, however, if you're looking at getting around Dubai, use the cabs. They are inexpensive, reliable and cheap - it's your best option. Monorail will take months more to be efficient and run to Jumeria and Sheik Zaid Road where it is needed. about 8 years ago
There's a monorail running from the trunk of Palm Jumeirah to Atlantis Hotel. However, I think you're asking about the Metro. If that's so, then no- it's scheduled to be operational starting on the 9th of September, 2009. (9-9-9, nice touch eh? :)) almost 8 years ago
The Monorail starts at the beginning of the Palm. The monorail ends at the Atlantis hotel. It is build for the Atlantis hotel. It is advisable to use the monorail in Dubai as it is a perfect way to see the highlights of Dubai. From the monorail you can make magnificent pictures and photos! It is also a very quick and it is cheaper than most of the taxis. about 6 years ago
I think you mean the Dubai Metro, and yes, this is up and running - from Ibn Bhattuta to Rashidya. Some stations further out are not yet open.
If you really meant the monorail, then this would only be the section on the Palm. about 6 years ago