First of all, there are two different treaties/programs of action - the UN Arms Trade Treaty and the UN Small Arms and Light Weapons Treaty. The second treaty has more potential to affect your gun rights. The next meeting for the UN Small Arms and Light Weapons Treaty is this July 2010.
However, no treaty is superior to the Constitution. For us, that means that no treaty can be stricter than the decision handed down in Heller
From the political reality standpoint, a treaty requires approval by a 2/3 majority of the Senate. Currently, there are nowhere near 2/3 antigun Senators in the Senate. On the contrary, the number of antigun votes is probably not even a simple majority. Also, the current Senate Majority Leader, Harry Reid, has been a consistent vote against gun control and faces a difficult midterm reelection. The chances of any UN treaty affecting U.S. civilian firearms ownership making it through this session is next to zero.
Like always, this can change if we do not elect the right people or stay vigilant in defense of our rights; but right now, I'd rate this threat as minimal until after Feberuary 2011. At that point, it will be time to look at the results of the 2010 midterms and see if the threat has decreased even further or has increased.
One more note on political realities:
WASHINGTON (Reuters) - The United States reversed policy on Wednesday and said it would back launching talks on a treaty to regulate arms sales as long as the talks operated by consensus, a stance critics said gave every nation a veto.
Like most politicians, this Administration is playing a shell game. They want to "look like they are doing something" for their base; but they realize that actually doing something would be suicidal. As Russia, China, and a number of other countries have signifcantly less restrictive arms trade regulations (remember this is ultimately about import/export on the international level) and make a great deal of money this way, the Administration gets to pretend like it is "reversing" the previous Administration while at the same time knowing the likelihood of such a veto being exercised is practically 100%.