I'm a Live 5 and Max/Msp/Jitter 4 owner.
I am happy with my current software, but to use M4L it sounds like I will need to upgrade to Live 8, Max 5 and M4L.
M4L does sound like a dream, doesn't it?
However, that's a lot of dough.
I know that I don't technically have to upgrade to Max 5, but it doesn't seem to make sense to be using 2 different versions, especially since the versions are so different from each other.
I'm really hope that they treat owners of both REALLY well. And, don't forget about owners of previous versions. Just because I don't upgrade every year does not mean that I haven't spent a lot of money on their products so far! Okay, the waiting game begins.