I'd say that's about right.
AirTran has a very large core of pilots who are in their 30's and 40's. It's one of the contributing factors to what killed T.A.'s 1 & 2; there isn't a huge group of close-to-65 (60 at the time) pilots who are worried about being unable to start over somewhere else (not that anyone is really worried about that).
I'd say about 20 people a year will either retire or have medical issues that take them out for the foreseeable future. Then you have the people who will leave for Delta or Southwest as they start hiring again (likely mid- to low-seniority F/O's), probably another 20 a year. The majority of upgrades and new-hires will come from deliveries that start next year, not to mention improvements to the Scheduling section from negotiations requiring better staffing, especially in Reserve coverages bumping us to 6 crews per aircraft (estimated).
So, figuring 6 crews per aircraft and adding expected attrition to that gives the following WAG on upgrades/hiring for the next 5 years:
2010: 0 New Aircraft / 159 new hires / 20 CA upgrades.
2011: 7 New Aircraft / 100 new hires / 60 CA upgrades.
2012: 8 New Aircraft / 120 new hires / 65 CA upgrades.
2013: 6 New Aircraft / 86 new hires / 45 CA upgrades.
2014: 12 New Aircraft / 160 new hires / 90 CA upgrades.
2015: 8 New Aircraft / 120 new hires / 65 CA upgrades.
2016: 10 New Aircraft / 140 new hires / 78 CA upgrades.
In other words, in 5 years, someone hired today will be 1/3 of the way up the seniority list and nearly 75% of the existing F/O's will have upgraded with still another year and 10 more aircraft deliveries in 2016.
Theoretically... it's all a crap shoot, anyway.

I'm personally betting on either a new, large aircraft order or a merger/purchase within 3 months after negotiations are complete.