You're preaching to the choir my friend.. that said it is always good to have another person make that request..
(try this thread for more comments, and a poll) http://forum.kalypsomedia.com/showthread.php?tid=13944
but i have not see any offical word on anything coming. but from what i understand timo stated that T4 has sold better than aniticipated, though not sure i have seen mention about how MT or the other DLC has done.
Many would love to see a sandbox/challenge check box feature that would disable building removal on the timeline feature. (i can understand that this doesnt have to work under the campaign.
I'd also like to see some features added to the builder. Mainly more graphical terrain options that could effect tropicans and tourists
rocky mountains, and large rock placeables
mountain tunnels.. (placeable in the builder but you could connect roads to them as well.
hot springs/guisers (think old faithfull, or hotspring pools for tourists, set up a spa on them for increased ratings, possibly tourist could use the pools
mud baths, On the same line as above..
if love a modders DLC...