I've just uploaded a pre-compiled-for-Windows RMagick 2.0.0 gem to 
RubyForge. The gem is bundled with ImageMagick 6.3.7-8. Look for 
RMagick-2.0.0-ImageMagick-6.3.7-8-Q8.zip in the rmagick-win32 project of 
the RMagick download page [http://rubyforge.org/frs/?group_id=12]. 
Remember it takes a few hours for the mirrors to catch up. This makes 4 
RMagick releases in 4 days so I'm going to stop for a while.

You can read about RMagick 2 here: http://rmagick.rubyforge.org/rmagick2.

How do you know if you should upgrade to RMagick 2? You should use 
RMagick 2 instead of RMagick 1 if

1) You want to use RMagick with Ruby 1.9.0. RMagick 2 works with 1.9.0. 
RMagick 1 does not.

2) You want to use new ImageMagick functionality. RMagick 1 maintenance 
is limited to bug fixes. New ImageMagick functionality will appear in 
RMagick 2.

3) You want to have better control over RMagick's memory usage. RMagick 
2 has two new methods - Image#destroy! and Magick.trace_proc= - that can 
help you manage the memory used by images in your programs.

You should stick with RMagick 1 if

1) You want to use older releases of ImageMagick or Ruby.

2) You want to use RMagick with GraphicsMagick.

RMagick 2 has different prerequisites and is very slightly incompatible 
with RMagick 1, so be sure to read the web page before you download it.

The detailed ChangeLog is here 
[http://rubyforge.org/frs/shownotes.php?release_id=17446]

Please report bugs on RMagick's bug tracker 
[http://rubyforge.org/tracker/?group_id=12]. You can ask questions in 
the RMagick Help Forum [http://rubyforge.org/forum/?group_id=12], or 
contact me directly at rmagick AT rubyforge DOT org.

RMagick 2 is an interface to the ImageMagick (www.imagemagick.org) image 
processing library. RMagick supports more than 90 image formats, 
including GIF, JPEG, and PNG, and comes with comprehensive HTML 
documentation.

-- 
RMagick: http://rmagick.rubyforge.org/
RMagick 2: http://rmagick.rubyforge.org/rmagick2.html