My view is when you got a new coach, brought in role-players that generally fit the system, have two all-stars on the team, and just demolished the expectations for wins in the first year together with your new coach in making the playoffs and taking the previous year's champs to 7 games (and, frankly, should have won the series except for the Stomp and a couple of broken hands, etc.),
IMHO you have earned the right to contemplate a championship run the next year when:
- you now can start off with a year's experience under your belt with the coach and his offense instead of playing catch-up at the beginning of the season
- many of the other teams in the west have arguably gotten worse (still very competitive, mind you, but arguably worse); see the Captain's post on this elsewhere
- you upgraded the bench significantly adding the Euroleage MVP and deadeye shooter in a position of need who apparently will fit this offense perfectly based on his skills and off-ball motion, brought in a better defensive player at backup center, upgraded the deep bench positions with youth and defense, and brought in a good friend of your all-star center to help fill the guard rotation that was very promising his rookie year before injuries in his sophomore year
- lost absolutely nobody in the core rotation; in fact, you extended two players who contributed significantly to your success last year ("max" extension for your all-star center and a team-friendly contract for your veteran "stabilizer" on the floor), guaranteeing stability and not feeding into questions about contract status/trades throughout the year
- and have total buy-in up and down the organization with the direction of the team, the coaching, the players we have, and the goal of winning a championship clearly stated by the front office and coaching staff and players