Finishing the main scenario and getting started on the gear treadmill is the only tricky and time consuming part. As soon as you can meet the ilvl requirement to queue for high level dungeons you earn a ton of soldiery from first time completions, and you can get geared really quickly. I went from pretty much fresh 50 to clearing World of Darkness in the space of about four days of solid play, so two months playing a few hours a day should be plenty.