The ICANN community here in Singapore is celebrating after the historic vote to expand top-level domains (TLDs). And while I wouldn’t begrudge anyone a few Singapore Slings, I think it’s a little early to start celebrating. The marathon effort ICANN began 5 years ago isn’t even close to reaching the finish line.

Actually, marathon is probably the wrong analogy. Try this:

A month from now, our host city of Singapore will welcome competitors to the 10th International Triathlon. What makes a triathlon so uniquely challenging is that after you complete a grueling swim and punishing bike race, you still have the hardest stage ahead of you: a long-distance run.

That’s where the ICANN community is now—just off the starting line for the longest and hardest stage of the race. How we run this stage will determine whether or not new TLDs succeed from the standpoint of the stakeholder groups that really matter: domain registrants and Internet users.

The first stage of the TLD triathlon—the open-water swim—was a painstaking, community-driven policy development process that took the better part of five years. It had all the feeling of a swim in the open sea, requiring constant movement without much forward progress. But we eventually stumbled onto the beach only to begin an unexpectedly contentious stage two.

The second stage of the TLD triathlon—the bike race—was the ICANN Board’s six-month saga of high-pressure, high-stakes negotiations with the Government Advisory Committee. Like a bike race, it was fast and dangerous, putting at risk everything that was accomplished in the prior stage. Monday’s 13-1 vote in favor of TLD expansion was like the race stage, where you feel grateful just for having survived.

That brought us to what I and several board members called “the end of the beginning”. Now ICANN faces stage three: the long-haul work of implementing the most ambitious undertaking yet.

This next stage is no victory lap. The global Internet community—including many stakeholders who weren’t satisfied with the outcome of the policy development process—will be watching ICANN’s every move to find an excuse to supplant its multi-stakeholder model with traditional multi-government models like the UN.

ICANN board resolution leaves enough unfinished business for stakeholders to spend the next year tweaking the “final” guidebook, even as ICANN’s foot-weary staff does the difficult work of putting it into effect.

During this stage of the race, ICANN must uphold its signature commitments to accountability and transparency. As the process evolves in keeping with today’s resolution, ICANN must also uphold the multistakeholder model and avoid any closed-door, staff-driven shortcuts that might seem expedient as the running gets harder.

Given the timeline approved this week, we’re likely to see our first new gTLDs sometime in 2013. If we all start running now, we can finish the TLD Triathlon and throw a real party—in about two years.