DPS is a quotient and not used generally for actual game equations (mechanics). Think of the DPS number listed in the tool-tips as a useful note, but not a part of the mechanics. SS is calculated from weapon damage (avg.) and effected by normalization, but not calculated from it. As in: Dmg + (AP/14)*2.4 + 68 = base SS-rank8 Dmg, where 2.4 is main-hand normaliztion for any 1-hand but daggers.
Check out
WowWiki's page on the SS with equations.
NOTE: There are some basic mechanics that are changing for the 3.0 patch (zomg, Evis!!!) and, far as I know, there isn't a ton of analysis on the new math just yet. There's some effort to verify the info so far but until the patch actually hits there's no way to be sure. (but, ZOMG EVIS!!!)
Hope that helps ;)
*Edit: Damn it Theo, beat me while I was proof-reading!
Edited, Sep 18th 2008 12:17am by TherionSaysWhat