I managed to successfully apply the RUU update (Verizon). Thought I would explain what I think my problems were for others who may be considering:
1) Firewall/ antivirus - blocked search for appropriate qualcomm driver that enables RUU installer to identify / find the phone in bootloader mode
2) Windows XP vs. Windows 7. Needed Silverlight and the device dashboard in order to find and load the qualcomm driver. Silverlight works with Windows 7 (my laptop) but not with XP (as far as I could tell). In either case, installation from laptop went perfectly smoothly. Most time consuming part was the numerous updates needed to find and load the driver. RUU was exactly 10 min - or even a bit less.
Even with official update (more or less) imminent, man was this worth it. Nicest changes so far - changes that may have been mentioned yet not featured in various reviews:
Larger screen area in browser. The layout has been optimized, to move URL status bar to the bottom and collapse what were the navigational keys into a menu. This enlarges the display by 1/3 inch from top to bottom. The entire display area is now used - and this difference is remarkably noticeable.
Battery Saver has been added to Settings menu. Options here include choice of two battery saver modes, and a battery status indicator including percent battery life, estimate time remaining on charge, and time since last charge. Got used to this w/ Android - missed it on WPphone, but not a deal breaker. Getting it now is bonus.
App-switching. Still rudimentary, but nice. You can see other open apps and navigate between them, however, they do reload to some degree. Example is Scrabble Helper, which does not save searches when navigating between apps. Better than before; could still use some refinement.
Color rendering is much better. This is most obvious on WPCentral site - the full blue screen that loads (when not using Board Express). What used to be the very rough and pixelated shading on the blue screen is much smoother, less pixelated. Nice.
Faster. Everything is faster and smoother (if that is possible).
For everyone in the "do you ever''' thread about playing with the animations for the sole purpose of appreciation, this will be renewed with Mango. The animations are even more amazing. When moving / pinning tiles on homescreen, all tiles move as if blowing in gentle breeze until all tiles are pinned back in place.
New NYTimes app, hit marketplace two days ago. Best Times app ever. I had (and did NOT use) the Android version, because it was awful compared to mobile site. This one is beautiful - in Metro font and layout, and again with the animations. As you tap a headline, it registers with a motion similar to the tiles on homescreen.
Live tiles - lots of changes, but I use those less. I don;'t use Xbox and have not yet started w/ Zune for music, so lots for me to test yet. Pictures tile is now live, rolling a set of three images at start before stopping on the third one. Nice.
Should be soon for everyone; just saw latest News post here on WPCentral about the confirmed launch of Mango for Vodafone tomorrow, Sep 21. It's pretty sweet.. . and since VZW are likely to be a bit longer, I am glad to be enjoying it now.