I just installed WWM 1.0.4 yesterday and I am very pleased with it. It does enough without doing too much (as other PPC Weather programs do IMO) and the price is right too! 
On my WM5.0 PPC (HTC TyTN), the short date format is set to “dd/mmm/yy” and this works fine for the “last downloaded time” but for the “last updated time” it shows “08//07” instead of “08/Feb/07”.
I don’t think a Today plugin is necessary as I don’t need to see the weather data every time I turn on my device and I’m already struggling to fit everything I need on the tiny screen.
I can’t connect to the internet to update the forecast (from WWM) at work through a proxy (who requires identification) even if PIE works and is configured properly. However I also use Pocket Opera and it too cannot connect from the office. This is of course via ActiveSync. At home, everything is peachy, wifi and ActiveSync.
Thanks,
Daniel