The junction with the Southern main line near Poole has been built on with industrial buildings, so resurrecting the original route would be difficult. Further up, the route has been used for a major road which carries a volume of traffic from Poole to the north. At Broadstone a sports centre occupies part of the station site blocking the former Right of Way. Further north, bridges are missing and probably there are more houses on the site. Thus reopening the route on the original alignment would be quite expensive and is very unlikely. If the route were considered worth reviving large lengths would need to be on completely new sites. And the gradients are still a deterrent to modern speeds, even with modern traction.
If the track had not been removed I think the line would now be considered commercially useful, but revival is not very likely. Although there are population centres at either end of the line there is very little in between - only small towns.
From Broadstone there was a link to the original line through Wimborne, built before Bournemouth was a town, which carried traffic from London and Southampton to Poole, Dorchester and Weymouth. That line lost its traffic to the new direct line through Bournemouth. The local traffic faded away so the Wimborne-Ringwood line was closed 40 years ago. That route too is now blocked by housing, new roads and bridgelessness.
