Originally Posted by John Clark
4Gb has been the current limit for quite some time (since 4.2.1 came out a year ago.) 8Gb is supported on 4.3 and higher devices.
Even so, there's no technical limitation to putting partial maps on 2GB. Plus, the database (essentially a permanent map cache) could be split into multiple files, each under 2GB, to cover a specific region of North America.