When I first heard this I thought it was being discontinued, but it's nice to know it will keep going. Really the move makes sense. How often does an email client really need updating, short of possible 0 day exploits that are found? Especially with open source where lot of people go through the code and will catch issues before it goes live.
I like having full control of my own email and have it hosted on site, thus I host it all on my home server. I use imap to access it, and Thunderbird does a great job at that. The fact that it's cross platform is a bonus as it means I can set it up on multiple computers/installs/VMs and all access the same email database.
It's also incredibly fast at managing large amounts of mail. I tend to let my spam folder go in the >50k range and I can browse through it like a walk in the park, select large chunks, or the entire thing, delete, and everything is fast. Try doing that in outlook.