Since February 16 last, many Canadian companies in all sectors have been able to take part in projects that will be funded under the US Recovery Act, that is under the American stimulus plan.
Furthermore, as Dany mentioned, pursuant to a permanent section of the agreement, the Americans are committing to keeping their government contracts open, in line with the commitments they made under the WTO's Agreement on Government Procurement. These provisions did not exist before. Canadian companies can now invoke them.