There isn't a David vs. Goliath element to this Thunder-Heat series, particularly with Kevin Durant and LeBron James going head-to-head to win their first NBA title, respectively.
But there is, however, a philosophical debate that was happening long before the stars aligned for these teams to meet in the NBA Finals. As Vince Thomas notes at The Shadow League, several of Miami's players were attained through free agency because of the desire to play with grand production of James/Wade/Bosh.
Oklahoma City drafted and traded for most of their guys and have taken a much more traditional approach to prominence that Miami. In terms of team development, this Finals could settle a debate that essentially focuses on substance vs. style.
This from Vince Thomas:
There's a philosophical debate at stake in this series, too. Four of Miami's seven-man rotation (LeBron, Chris Bosh, Shane Battier, Mike Miller) have come to the squad within the past two seasons - all as free agents. Of OKC's seven-man rotation, only Perkins is new and the rest, other than Thabo Sefalosha, were drafted by the Thunder (or Sonics). And Perk and Sef' came to Oklahoma City via prescient trades. Miami built its contender based on Wade the Recruiter, Pat Riley the Don and South Beach the Allure. OKC built its contender based on patient, smart management. Miami was a destination; OKC is a farm-system. The OKC-way is far more impressive.