A new Year's Speech can be given by an employer for his workforce or it might be an informal toast within a group of friends who are celebrating the New Year.
If you've been asked (or are expected) to make a formal speech please don't drink until after the speech. Look back on the year and point out some of the highlights and then look forward to next year.
As this is New Year celebrations expect your listeners to have had an alcoholic drink or two. This may make them a little less likely to want to stand (or sit) and listen for a long time. If you know that they'll have been drinking for quite some time before you speak, try to shorten your speech a little and make it very informal.
Make sure you leave plenty of pauses between each new thought so that the listeners get a chance to take in what you've said.
Your listeners will appreciate giving a short speech with adequate pauses much more than to give a longer speech full of more information but spoken so quickly that no one has a chance to understand it.
If it's an informal party with friends then a quick toast will be fine.