Acer in Australia and New Zealand announced last week that an official update to Android 4.0 Ice Cream Sandwich, would arrive for the Acer Iconia A500 tablet in April. If you don’t want to wait that long, you don’t have to.
If you’re willing to flash a ROM onto your tablet (at your own risk) than the community minded folks at XDA have found an Ice Cream Sandwich ROM for the Acer tablet and have released it.
XDA gives full instructions, links and feedback right here. As usual you’re doing this to your device at your own risk.