Yeah, Apple would never update such a new product so soon after introduction...
..except that it is exactly what they did with iPod Touch and iPhone when they were first introduced.
What's so un-Apple about improving a good product?
First, your "facts" are plain wrong:
The second generation iPhone (3G) was introduced 1 year after the classic/2G (actually the time between introduction was even longer, if you count the first generations introduction in january and availability in june!!!). iPhones are on a 1 year schedule since the classic.
All iPod Touches have so far been available in September (introduced a few days earlier). Including the first and second generation:
1st generation: September 13, 2007
2nd generation: September 9, 2008
3rd generation: September 9, 2009
4th generation: September 8, 2010
Apple won't introduce an update to a mayor productline in the midst of the shopping season. That would lead to many upset customers bringing back their "old" iPad, that has just been bought as a present.
Apple can barely keep up demand with the current generation. Why for gods sake would they introduce another one with shortages, while the current generation sells like hot cakes.
Apples product cycle on almost all productlines is exactly one year (computers slightly less, software more).
So, if you want to hope for a new iPad this year, nobody stops you. I would bet big $$$ against this.