Monitor manufacturers are changing things up by not only offering more IPS panels, but changing up the screen sizes between 21 and 25-inch. Dell launched a 24-inch UltraSharp monitor a few weeks ago based on an IPS panel and with a few trade-offs were able to get the price down considerably when compared to the U2410 which is aimed at the professional market. Mitsubishi, AOC and Viewsonic are already offering or at least, expected to offer 23-inch IPS-based panels this year.
Why the explosion of interest in IPS panels? You can thank the demand of the iPad 2 and the promise of wide viewing angels. Compared to monitors using twisted nematic (TN) panels, IPS panels are about $35 more expensive to make and that number escalates when the screen size goes up. Monitors using IPS panels are also feature-packed, usually including USB hubs, extra video inputs and so on, which also drives the price up.
I think it's a great move, IPS panels are gorgeous and if we can see a mix of 120Hz/3D-capable IPS panels in the near future, well count me in as excited.