According to the allnovascotia.com, Halterm will be getting two new post-panamax cranes by April of next year. Also Maersk will be building 10 very large, super post-panamax ships that can each carry 18,000 TEU's. Although these won't be calling at Halifax, it will free up other super post-panamax ships in the 8,500 - 13,000 TEU size range for the Atlantic route.
There are also plans to fill in several piers at the north end of the Ocean Terminals which is the Halterm terminal -
Ocean Terminals Map . Work on the 40 acre expansion won't start until 2015 - 2016 once traffic pick ups (which sounds likely according to the story).
Things are looking good for the Halifax port traffic.