Google Voice Search is apparently now finally available to download from the iTunes Store. However there's nothing different about the iTunes app that I can tell from the associated copy.
But here's the Google mobile page that offers a link directly to the iTunes store to download the updated app.
The "first impressions" are are now coming in quickly: some people love it, some are giving it a more qualified endorsement. So far no one is highly critical of it. Here's the complete blog roundup on Techmeme.
What people should remember is that this is the beginning of something . . . We'll have our own take in the near future.