I have summarized all proposed changes on http://meta.wikipedia.org/wiki/Thumbnails
Marco Krohn wrote:
it might be a solution to modify the code, such that
[[image:bla.jpg|thumb|200px ...]]
gives the old result and
[[image:bla.jpg|thumb|~200px ...]]
means that you want something which is roughly ~200 px
So funny, I thought of the exact same syntax befor I reached your mail in the thread. Must really be intuitive! :-)
Magnus