"We're excited to announce the availability of Google Maps for mobile version 2.3 with Street View on Nokia S60 and Windows Mobile. Street View was previously released on Google Maps for Android, BlackBerry, and iPhone. Street View lets you access street level imagery to help orient yourself when looking for places, businesses, or getting directions. Say you're going to meet with friends at an unfamiliar restaurant. Now you can search for it in Google Maps for mobile, click on "Street View", and see what the place and surrounding area look like. Similarly, say you need to get to a shop in a part of town you don't know. Find it using your phone, get directions to it, and see how to get there with full-screen panorama images of every step along the way."
Google Maps 2.3 has arrived, but this release is more than just a bunch of bug fixes. It includes walking directions, transit alerts, POI reviews, and Street View support, so you can take the sights of the United States, Australia, France, Italy, Japan, New Zealand, and Spain with you wherever you go. It's a free download from google.com/gmm.
I had trouble finding the WinMobile version because I have Opera Mobile set as my default browser on my device. Apparently Google tries to predict what device you have, and only offers the WinMobile version if you're browsing in Pocket IE.
In case you're wondering, here's the direct link to the Windows Mobile version.