SGS2 won't see JB till Q4 and even then it will be a few weeks at least till MIUI use it. We could be waiting till next year. So yes they should bother with 4.0.4.
I'm beginning to think SGS2 isn't even being worked on, we have had the same bugs list for weeks!
What makes 4.0.4 so much better than 4.0.3?