It’s got three mic capsules, allowing you to record from the front or rear at both 90 and 120 degree patterns. (Could be interesting for recording roundtable discussions?)
It doesn’t have the expandability of its bigger brother (the H4 accepts 1/4 TRS and XLR mic connectors while the H2 has only a 35mm mic connector), but it does best the H4 in it’s USB connectivity (the H4’s USB 1.1 vs. the H2’s USB 2.0 support) and SDHC support (the H4 supports only 2 GB cards while the H2 supports 4 GB). Pro’s will like the H2’s support for Broadcast Wave Format which isn’t available on the H4.
According to Engadget, the H2 will be available in May for around $200.