So, about the coming features. I will address each one separately, first the top three of the list I posted earlier.
Mine Shaft
I have seen this idea to be thrown in several major mods, though so far I don't know any major mods that actually implemented it. The idea is to have a special workshop called "Mine Shaft", which can be used to produce all kind of metal ores without actually mining them from the world. This is to provide at least some kind of source to useful metals (all layers filled with Galena veins only, anyone?) as we currently have no way of knowing the layers of embark location before actually embarking. Found a nice spot for a fortress only to realize there are no copper, gold, silver, iron or coal around? Happened too many times for me and Dwarf Fortress Advanced somewhat requires you to have some kind of defenses set up early on.
Now, the list of ores I will include in the first version are iron ores, native gold, native silver, native copper and coal ores. To compensate the easiness and perhaps cheesy way of getting all the metals the chances of actually producing any ores are fairly low. That means it's more or less always better and faster to actually mine those veins than rely solely on the workshop.
The current idea for the rates is that the total rates (ie. with iron ores the combined chance of producing any of the ore) shouldn't be over 25%. This may change along the way though. The construction of the workshop and all the reactions require mining skill, though currently no war picks are required.
Farmable Tree
This should be quite easy concept to add. Basically it will be a new plant which can be planted in underground farms and then harvested and finally produced to laminate in lamination workshops. This means no more tree farms, which are hard to control, and relying on caverns/surface. This would be especially good thing for fortress built in harsh biomes with only few or even no trees.
There are two things I must consider with the new tree; the value and growing duration. The value should be quite low, same as the lowest value of native trees. The grow duration is more a problem, as too long will make the farms more or less unusable but on the other hand too short duration will break the balance.
New Version of Temples
This feature was inspired by the Dwarven Lamination mod, which basically included four different versions of each workshop; one workshop for each direction. As the temples have very restricted point of access, only two tiles not blocked in altars and three tiles in temple, offering version for each basic direction should be a good idea. This one should also be very easy to implement as it doesn't require any new reactions, only copying the current altars and temples and modify the structure and finally add the new workshops to the religion reactions. Easy to do though perhaps a bit boring due all the copy-pasting.