Messenger 5 / MSN 6.0

Ok so I have installed Messenger 5...

Disregarding that it looks like they removed more features then added....

What is the game plan here? I am way beyond confused. If I install
Messenger 5 I am not capable of doing most anything with MSN 6. If I remove
Messenger 5 I lose several features which I really need to use with some of
my contacts. If I install both I can only log on to one at a time first of
all and second it means an extra program running.

So like could someone please explain this to me.

I have got to be missing something here.

Thanks,
John