The first reviews of iTunes for Windows have been filtering in since its release. OSNews provides their first impressions of iTunes for Windows. Overall a favorable review, though the author has some significant issues with User Interface performance on her computer.
Other potential issues mentioned in discussion forums across the web include high memory and CPU utilization by the new Apple application. These complaints, however, are not universal -- with several users reporting excellent performance and unremarkable RAM utilization. Obviously, user experiences appear to be variable at this time.
Apple has already released a number of Knowledge Base articles to provide assistance/instruction for iTunes for Windows:
