The tool gives directly an update file but I don't know where it is host, so I don't have any address to give.
That's why I put the whole file as an attachment in my last message.
I'm a French owner of A500 and my tablet had received ICS via OTA yesterday 23th of April
kernel version : 18.104.22.168+
Android version : 4.0.3
Image version : Acer_AV041_A500_RV03RC01_WW_GEN1
Build number : Acer_AV041_A500_1.031.00_WW_GEN1
Image Ref : FM.S14A0.00U