You are in the same position as me i was looking at the base model 21.5" for quite a long time but then i decided that i would wait for the update and get a base model 27" iMac i hope that by doing this i will get more for my money and also that it will last me longer without having to upgrade in just a few years. If i was you i would just get the base model iMac when the update is released this means you will get more for your money and yes it should last a little longer because i have heard many people say on this forum that the components in the base model iMac 21" are quite old and really need an update such as the nvidea graphics card.