I use my ipad 2 quite heavily for work related activities as well as entertainment. I like it so much, and want for so little, there is no need to upgrade. Hell, Apple still sells a mini with an A5 chip in it. The ipad 2 will work well for years to come.
If Apple wanted to push ipad sales, it would more aggressively upgrade the chips in new models so that software leaves the old ones behind.