The first regional bloc update, ECOWAS (West Africa), focused around the Federal Republic of Nigeria, will be coming out just before 1.5 in some guise, then I'll be doing bug fixes around when 1.5 drops, then I'll be finishing off the rest of the ECOWAS stuff afterwards in a second patch.

A playable (but not finished) Nigeria tree will be in before 1.5, AI logic specific for each nation in the region will definitely be in (although not historical focuses, yet), updated Orders of Battle, and various other bug fixes from the current build. The ECOWAS regional focus tree probably won't be added until after 1.5, as well as historical focuses for the region.

Some gameplay highlights will include the WAMZ/UEMOA economic divide (and the eco/franc currency question), federal challenges for Nigeria (Oodua, Biafra, Boko Haram), more options for larger factions (a politically-biased 'Federal States of West Africa' and a militarily-biased ECOMOG pact) centered around Nigeria, an ECOMOG alternative to the AU peacekeeping tree, and a whole lot of corruption flags. The Nigerian seperatists will not have custom nations initially, but that's scheduled for the second release (v1.12).

Nigeria plays as a sleeping giant. It is plagued by obscene handicaps (such as oil debt, piracy, smuggling, confraternities, low morale, human rights abuses, separatist movements, religious strife, etc, the list goes on), with the constant choice of quick-win short-term fixes versus much tougher long-term revisions. Ignoring any one area in favour of others will greatly stunt growth in those areas, but you can't do everything at once. If you choose the hard options and push through the difficult routes, Nigeria can emerge as the true Giant of Africa, dramatically shaping the region with a focused vision and massive economic + military potential. Alternatively, if you want you can try to push Nigeria's weight around straight away you can satisfy the corruption, crackdown on separatists, and see if you can succeed in a reactionary approach where successive real Nigerian governments have failed.

For other nations in ECOWAS (in the later patch), there will be a number of choices added to the standard focus tree. Militarily, you can choose to align with the ECOMOG or AU. Economically, you can choose WAMZ or UEMOA, and choose what currencies to adopt. There will be some events and other additions for critical bit players in the region (e.g. Sierra Leone) to add flavour.

After ECOWAS the plan is to focus on bug fixing, refactoring, and updating some of the core mechanics to take advantage of expansions (whilst remaining backwards compatible, ofc) and updates to Millenium Dawn. The code is pretty bug-ridden and needs a lot of love. By the time the ECOWAS update is done it will potentially be over 200 files, with enough text context to rival a novel. The mod will be feature frozen at this point. I will need to merge MD's updates with AC before moving on the next regional update; that's a truly mammoth job (involving picking through that entire 200 file base and manually cross-referencing it with all the updates to MD) which will cap off v1.2.

Finally, I'll be looking to the next regional update for v1.3. I'm still musing on which region will come next.

v1.1 (First ECOWAS feature update) will hit prior to the 8th. This is mainly the Nigeria focus tree drop, OOBs, and foreign relations, with some other improvements.
v1.11 will happen around early to mid March. This will include bug fixes for ECOWAS and fixes stemming from the new expansion + MD update.
v1.12 (Second ECOWAS feature update) is being targeted for early April. This will contain the ECOWAS focuses, unique nation events/minor tree branches, polish the regional update with stuff like historical focuses (setting the quality bar for every regional update to come), and finish off Nigeria. Note that this isn't the final look for the nations of ECOWAS - minor nations (Ghana is of particular interest here) will still be eligible to receive updates in the future between other major regional bloc updates. Africa is a big, big, place.
v1.2 and onwards have no release date.