With everything said before ^^^, I have taken three solo trips the past three years in Oct 2007, Aug 2008, and Dec 2009. I have been to WDW numerous times with the family when I was younger, but visiting WDW, Universal, Sea World, Busch Gardens solo adds a whole new dimension.
I could do things when I wanted, and at the drop of a hat change my plans completely and go in a different direction. With the exception of attending the Halloween and Christmas parties (set days), it was time to fill when I got off the plane and when Mears picked me up to get back to the airport.
Disney is many things to all, including those taking in WDW solo. In addition to Universal, Busch Gardens and Sea World, I loved that I could by-pass most of the queue in favor of the single-rider line (Everest, RocknRoller Coaster, The Mummy, RipRideRockit, Test Track) and be on the ride quicker than most in others (Manta, Kraken, Tower of Terror, The Hulk, Dueling Dragons/Potter Dragon Challenge) when the staff asks if there any single riders. You luck out sometime sitting in the first row or the last row on rollercoasters sometimes.
Take it in stride.
Btw, it's your time. Spend 16-18 hours at the parks or spend a few hours on a behind the scenes tour. Indulge yourself with the specialties of Disney or go sparce and be a ride warrior and eat counter service. Strike up a conversation in the queue, or not. Help dad or mom take the family photo. Slow down speed up, and see things differently on your solo journey.
As for meal plans and table service, I did that three times -- I stopped by the Sci-Fi Dine-In and within 20 minutes came back and had a seat. It was in the back seat of the car with a family in the front seats, but it was awesome. The cast member said the family picked up a hitchhiker on the way to the drive-in. Second time was at the Brown Derby and third was at the 50s Primetime. Both times I was sat within 10-20 minutes. Did not need a reservation. Never a dull moment.
Also if you speak another language, as in the World Showcase countries, strike up a conversation with some of the International cast members. I did this in France several times during my December trip.
I made it a point to order en Francais and as well improve on diction and learning new things about France / Quebec and the cast members.
In October I will make four years solo at a Disney property. I'll be in Anaheim to visit Disneyland and Knott's Berry Farm.
Best of luck with your plans.