Good news for those of you patiently waiting for Acer's April release of Ice Cream Sandwich for its A100 and A500 tablets: the good people over at XDA seem to have found stable leaks of the update ready for your flashing. XDA forum member vache posted the files today, and says that the leak is running quite nicely on the A500. A quick look through the forum posts indicates that the leaks are smooth and relatively bug free, though the upgrade will indeed remove root access on your device.
Despite the good reviews, keep in mind that the files are not Acer's final build, and thus can come with a hidden bug or five. If you're feeling brave, you can grab the files at the source link; to flash, you'll need to rename the file to update.zip, place it on the root of your SD card, and boot into recovery. If the process sounds like gibberish to you, you might want to sit tight for another month for Acer to roll out the official OTA.