"Doc"...I am so impressed! Not just with the mountain bike challenge but the rest of your life! Med school huh?...Way to go!
How old are your kids? I found after i was divorced (13 years ago with two little ones, one with special needs) i found a whole new life, a whole new "ME" and best of all....am remarried and still finding this new person! Sounds like you are a stong person all the way around. Although you'll be challenged, you'll do GREAT!
Re: getting a road bike...how about asking around in you LBS for used ones. I think "roadies" tend to baby their bikes so you'll prob. find one that is 'gently' used. orrrrrr...when's your next birthday? I've been requesting bike stuff for my birthdays, Christmas, etc...
All the best to you in your "next phase" of life! You're going to love it!

"Cy-newbie"... I have a Specialized Allez. I looked at the Siquoia (i know i spelled that wrong!!!) too and my brother in law who has an Allez already talked me into not getting it. I'm sure it's an awesome bike. Check the components...The Allez is all Shimano Ultegra (wow, i'm a bad speller!!!) and i think the Siquoia is mixed? I can't remember off hand what it was that sold me on the Allez. Anyway, you'll like the Specialized bikes.
I was riding a hybred and bit the bullet and can't wait now for warmer weather to get out there!!!!!
I too am nervous about traffic and am hoping to find some routes that are on the quiet side. I would have no problem on my old bike but the clipless thing is what is making me nervous! (that i won't be able to unclip in traffic!!!! AHHHHHH!). I about fell off my spin bike yesterday because i couldn't get one clip out....try to manage that one. DAH!!!!!!!!!!!!!!!