Vineviz has described L389 as an option for testing in the R1b asterisk project.http://www.familytreedna.com/public/r1b1asterisk/default.aspx?section=news
I've also seen a diagram where L389 is inserted right above P297 and M335. In other words, P297 (where M269) fits and M335 are brothers while V88 is a bit of a cousin.
The ISOGG Y DNA treee does not reflect this.
Is it firmly known where L389 fits? I've tried to depict what I think here, but I'm just looking at other peoples' notes.https://dl.dropbox.com/u/17907527/R1b_Descendancy_Tree.jpg
Vineviz's diagram also did not include P25 so an additional question is does L389 fit above or below P25? It appears that since V88 falls under P25, I think, that P25 is immediately above L389. Perhaps P25 will be removed from the tree anyway. I don't know.