Delta Air Lines signed a deal to acquire a 49% stake in Virgin Atlantic Aairways for $360 million, forming a strategic alliance that will dramatically boost Delta’s access to London Heathrow Airport and potentially provide a path for Virgin to restore its financial luster while retaining its brand and iconic leader, Chairman Richard Branson. But there are several steps the airlines need to complete to fully realize the potential benefits of the agreement—some that could happen in the short term but at least one of which could be years away.

The most critical need is getting regulatory approval for their planned joint venture, which would let the airlines move their arrangement beyond frequent flyer reciprocity and code-sharing to encompass joint pricing, capacity planning and cost and revenue sharing across the Atlantic. The deal also gives Delta three seats on Virgin Atlantic’s board.

Under the new collective bargaining agreement Delta reached with its pilots union earlier this year, the airline also needs to reach an agreement with the union on the “production balance” in the joint venture (JV), namely the percentage of block hours flown by Delta pilots on the transatlantic flights. Otherwise, as the Air Line Pilots Association has described it, the contract includes automatic limitations that will kick in “to ensure that the Delta pilots retain an appropriate share of flying in the new JV and continue to restrict Delta’s ability to sell code on its JV partner.”

Beyond those more immediate concerns, the airlines need to move closer together at Heathrow to make connections there more convenient. Delta currently operates out of Terminal 4 with its SkyTeam alliance partners, and Virgin Atlantic out of Terminal 3.

At a press briefing about the deal on Dec. 11, Virgin Atlantic Chief Commercial Officer Julie Southern says the plan is for Delta to move to Terminal 3, eventually, to ease connections and take advantage of Virgin Atlantic facilities there, such as its clubhouse and Upper Class Wing. “It’s not something we can achieve immediately with the physical challenges of a constrained airport at Heathrow, but we’ll work hard to try to make that happen over the coming years,” Southern says. She did not specify how, but one possibility is that the space could be created in 2014, when Heathrow opens its Terminal 2, the planned home for Star Alliance carriers and Aer Lingus flights and Virgin Atlantic domestic routes.

Location is not an issue at New York John F. Kennedy International Airport, where both airlines already operate out of Terminal 4. When Delta completes its expansion project at Terminal 4, Delta and Virgin will be co-located in the new section, Delta CEO Richard Anderson says.

Delta also stands to benefit if Virgin Atlantic joins its SkyTeam alliance, but Southern insists that decision has not been made. “There’s a lot of work to evaluate SkyTeam and the additional benefits that it can bring,” she says. But she adds that she expects a decision on the alliance to be made “over the next few months.”

Anderson says Air France/KLM, already joint-venture partners with Delta and Alitalia on transatlantic services, has expressed “strong support” for the Virgin Atlantic deal. But some additional work will be required with that joint venture, which got off to a somewhat rough start on transatlantic capacity decisions but seems to have resolved the issue during the past year. “We will be working with them over time to make sure we’re well coordinated between the two joint ventures,” Anderson says.