But the degree to which Eastern consumers will benefit at the pump is unclear, as it's up to the pipeline's customers — oil producers at one end and refineries at the other — to determine which barrels go where.
"One thing that I've learned over the years is the market will do what the market will do and it's difficult to predict beforehand," said Geoff Hill, oil and gas sector leader at Deloitte Canada.
The crude could flow to Eastern refineries clamouring for cheaper domestic supplies. Or, offshore buyers may drink it up. Most likely, it will be a combination of both.
"If you're a supplier of oil, you're going to be sending it to whoever gives you the highest price for it," said Hill.
"You're probably going to see a healthy amount of export as well as domestic supply, depending on the market for oil at any given time."
Calgary-based pipeline giant TransCanada Corp. (TSX:TRP) is in the process of determining what, precisely, the market wants out of its Energy East pipeline through a process known as an open season, which will wrap up in June.
Energy East involves configuring part of TransCanada's underused natural gas mainline between Alberta and Quebec to handle oil, as well as laying down a chunk of new pipe to the East Coast.
The line, which could carry up to 850,000 barrels of oil per day, would deliver crude to refineries in Montreal, Quebec City and Saint John, N.B.
TransCanada rival Enbridge Inc. (TSX:ENB) has a plan of its own to reverse the flow of an existing pipeline between southern Ontario and Montreal — Line 9 — in order to send Western crude east. So far, it has not announced plans to extend it to the East Coast.
Eastern refineries have been struggling, as they rely on expensive crude imported from overseas. Most are configured to handle light, sweet oil, not the heavy stuff produced in the oilsands.
That imported oil follows prices of Brent, a benchmark for light crude produced in the North Sea. Brent trades at a big premium to West Texas Intermediate, the inland North American light benchmark, even though the two are of similar quality.
Last year, Eastern refineries imported some 720,000 barrels of oil per day from overseas suppliers — many of which are far from being political allies — to meet virtually all of their needs, said Alex Pourbaix, president of energy and oil pipelines at TransCanada.
"There's a very significant prize," he said of the Energy East proposal.
Alberta oil prices, which themselves trade at a discount to WTI, should improve with the new Eastern market access, he said. At the same time, the ailing refineries should see better profit margins.
And consumers are likely to benefit to some degree as well, Pourbaix added.
"Just removing reliance on a higher priced, much more risky feedstock I think will have an impact on the perception of scarcity, which should have an impact on gasoline prices," he said.
"In any sort of market, if you add an incremental volume of supply to a fixed level of demand, you should see some price benefits."
Pourbaix expects that, at least in the beginning, Energy East will carry light oil. Large amounts are being produced in the Bakken formation, underlying parts of Saskatchewan and North Dakota, as well as central Alberta. Some oilsands producers also upgrade their crude into a refinery-ready product called synthetic crude oil.
"What we've seen so far is that there's been a lot of interest to use this pipeline to move light to the Eastern Canadian and Eastern U.S. markets."
But if heavy oil producers want to ship product east, too, the pipeline will be capable of moving both types of crude to various locations in batches, Pourbaix said.
Though the Eastern market is thirstiest for light oil, Irving Oil's massive refinery in Saint John can handle some heavy grades.
But it's not necessarily Eastern Canadian refineries that producers are eager to access.
Accessing the port at Saint John, N.B., would enable them to ship their oil, perhaps unprocessed bitumen from the oilsands, to lucrative overseas markets by tanker.
Oil company Cenovus CEO Brian Ferguson was frank about his company's preference in a February interview, saying it was the export option that was most enticing about TransCanada's proposal.
And Alberta has blamed its budget squeeze on insufficient capacity get oilsands crude to tidewater.
"I would say the real target here is to get it to the deep sea port at Saint John and export it either down to the U.S. Gulf or to India or wherever — whoever wants it," said Roger McKnight at En-Pro International, which helps clients manage their fuel and energy costs.
"I don't see how it's going to benefit consumers. I just don't see it."
Even if refiners do replace pricey barrels imported from overseas with cheaper Canadian crude, it doesn't necessarily follow that their lower costs will be passed on to consumers, said McKnight.
"There's some confusion here, because the prices at the pump do not follow the input costs of crude, they follow the whims of the Wall Street speculators," he said.
"So we could have situations where crude could actually go down, but the prices of gasoline could go up because the speculators see some geopolitical threat on the horizon and they're guessing that the price of gasoline is going to go up."
Also on HuffPost