Originated here: http://forums.b2evolution.net/viewtopic.php?p=88765

Idea: Make the Tags Aggregate-aware.

Variables:
Blog A is aggregating all blogs - 1,2,3,4
Blog C have a sub-blog called Blog D = Blog C aggregates itself (#3) and Blog D (#4) = 3,4
Blog D is not aggregating any blog.
There are posts tagged "TAG-01" in Blog C and Blog D.

Case 1:
User clicks "TAG-01" in Blog C.
It displays all posts tagged "TAG-01" from Blog C and Blog D - using the skin of Blog C.

User clicks "TAG-01" in Blog D.
It displays all posts tagged "TAG-01" from Blog D only - using the skin of Blog D.

Case 2:
User clicks "TAG-01" in Blog A.
It displays all posts tagged "TAG-01" from Blog A to Blog D - using the skin of Blog A.

Of course, only Blog C and Blog D produces results, as our variable above states that only Blog C and Blog D have posts tagged "TAG-01".

Hopefully for v3.x? ^_^