Just an FYI regarding Waves plugin updates....
 
It's been stated a couple times in this thread that there is no way to see if there are any updates.  That may have been true when this thread started, but that's not the case now with the current version of Waves Central.
 
When you start Waves Central and log in, it should say "Checking for updates" in the upper left of the window (In the black strip, just to the left of the word "Install").  If it finds any pending updates, it will prompt you to run them.  I've done this twice in the past couple months.
 
Regarding WUP.... I've renewed, but only when it was necessary, to sell some plugins.  In my case, I bought the Gold Bundle, and as a result ended up with dupes for seven individual plugins.  Five of them needed WUP renewal.  I did the math, and the result was that even with the $105 WUP fee, I came out ahead (with the $105 Waves voucher and the proceeds from the plugin sales), and basically ended up getting the Gold bundle for free.
 
So, WUP can work out in your favor, depending on how you use it.  But otherwise, my feeling is best to not worry about it -- at least until version 10 comes along.