What works

The installation works out-of-the-box.
The installed program needs a little more work.
Using the trick suggested in bug #10505:

copy a native usp10.dll into the windows/system32
and:  

$ sh winetricks jet40 
$ WINEDLLOVERRIDES="usp10=n" wine wiso2008.exe 

program seems to work fine so far. I'll continue to use it, to test every little feature

What does not
Online update did not get a connection.

What was not tested
Printing, Online submission of tax forms (ELSTER), Import old data

Additional Comments

Wouldn't work with OpenSuSE 10.3 upgraded from SuSE 9.2, fresh install required.