Blue makes a prosumer mic that you can connect directly to an iPod or iPhone via the dock port. I would love to have the same capability to do something similar for an Android phone or tablet. This would be really useful for field recording. I know that some tablets have support for various USB accessories to be plugged in, but I don't know if the OS can handle a microphone. Is this possible using existing or near future (Ice Cream Sandwich) hardware/OS combinations?
The range of USB device types supported "as is" by Android is limited and does not include microphones.
On the other hand, Android has the capability to work with an unlimited range of USB devices via their 'open accessories' sdk/kit/framework. This was added in Android 3.0.
I believe they had to do it this way: existing USB devices require driver support and they can't go adding all those drivers to Android (which is a static image). The open accessory framework will allow for devices that can be supported without loading a Linux driver.
So, you can't just go and buy a USB microphone and plug it into your Android device, but I expect we will soon start seeing USB accessories that are specifically designed to work with Android.
No, it's not supported on any Android version up to and including 4.0.3. (I've just tested this with my Zoom H4n and Asus TF101 upgraded to 4.0.3.)
There's no reason it can't be added in a future version, or maybe a third-party port. The driver exists in Linux, so it would just need to be included in Android's Linux kernel build and then given some interface for applications to get at the device.
It's still possible to use the H2 as a field recorder and then turn on its mass storage interface to access the recordings from a tablet or phone. It's not quite the same, and not useful for (say) Skype, but you could still use it for a record-edit-upload workflow.