The RTA have announced that Burj Khalifa metro station will be closed tonight so you will need to use nearby metro stations if you want to get to and from the fireworks in downtown Dubai.
Both the red and the green line of the Dubai Metro will be open all night on New Years Eve to enable people to get home from the celebrations. In fact the red line will be open non stop from 5.30am on 31 December until 1am on 2nd January and the red line will be open from 5.50am on 31st December until midnight on 1st/2nd January.
The RTA has made a change to the minimum balance that you must have on your Nol card in order to be able to travel on the Dubai Metro.
The minimum balance for Silver and Gold cards is 7,50 dirhams. This corresponds, on silver Nol cards, for the maximum fare for a single trip. This means that you should not be able to travel on the Dubai Metro with a negative balance on your Nol card which you could do previously. However, the maximum single fare for the Gold Nol card is 15 dirhams and so it is possible to travel in Gold Class with a negative balance (which will then be deducted from the next top up).
If your Nol card does not have the minimum balance on it then you will not be allowed through the automated gates at the Metro station. You will first need to top up your Nol card.
On the tram and the bus there are tap in and tap out stations and not automated gates, so in theory you can still get on the tram or bus with a negative balance. However, it is a violation to travel without sufficient funds on your card so you could be in for a fine if you do so.