Hey, Rene.
The windows install of JWS is of course terrific.
The Solaris install needs some work though.

1. HTML page
------------
This page:
http://java.sun.com/products/javawebstart/download-solaris.html

says
  "make sure the zip file you've downloaded is located where
   you'd like Java Web Start to be installed, usually your home
   directory. Unzip the file and then run the ..."

But in reality, you want to put it in a temp directory, and
not your home directory, because a lot of files are left over
after the install.

2. install.sh
-------------
When no arguments are present, the usage notes need to detail
the possible options. Currently, the usage notes say
  install <options> <directory>

Now, <directory> is obvious enough. But what are the possible
options. (I took a look at the script, but it was rather long
and involved, so I didn't discover what the options were.)

The expanded description might also make a suggestion for the
directory, as for example "~/javaws" to put it in a subdirectory
of your home directory.