I can't speak for the team as I don't know their plans. I can, however, mention a few things in response.
Yes, the switch from svn to git can take a few days, so think carefully about everything and just review things twice, there might be some pitfalls.
In my personal experience, if the Subversion repository has been well-managed, it will import well. The main SMF repository has been fairly well managed.
Also, I believe things have been going on for a few months as it's a big workflow change, so it's more getting the flow down than any technical issues.
BTW if you do not know it - smartgit is really a nice client! (no, not affiliated with them, it is really good software and free for non-commercial use!).
The team knows about it and many other clients. Personally, I just use the CLI interface, with gitk if I need to see something visually.
How are your plans for integrating mods into the repo? Are you integrating them at all?
I do not know their plans on this. I don't think it is under consideration as nearly all modifications are by third parties, most licensed in ways that you can't just take the code.
Would be interesting to read about what strategy you are planning for this - the absence of any plugin api will make every installed mod actually a new branch - leading to an infinite number of branches with random combinations of mods...
The developers have implemented a "hook" system since the late 2.0 RC stages. I believe this is the encouraged system to use for all 2.x modifications currently, and it avoids 90% of direct code edits.
Ok, I just found https://github.com/SimpleMachines/smCore - also http://www.simplemachines.org/community/index.php?topic=469381.0 reads like SMF is finally becoming a good modular design that enables better extendibility, very nice! Maybe it is better to look forward and get that 3.0 realized as fast as possible
Old news. smCore was announced on February 24 over in the News and Updates board topic Simple Machines is expanding
and in the development blog post The future of SMF
If you want to follow things currently, watch the News and Updates
board and the development blog