Four branches of I-M26 have been known for a few years:M26+ L672+
M26+ L277+ L247+
M26+ (L672- and L277-)
What's new is that several L672+ men and one L247+ man have completed Geno 2.0 tests. We learned that the L247+ man is ancestral for 17 SNPs that previously were thought to be equivalent to M26. Now the M26+ L672- L277- man is doing the Geno 2.0 test, and I expect that he will be on his own branch that split off even earlier, and he will be ancestral for some of the 36 SNPs that currently give results equivalent to M26.
The Mexican-American M26+ L277+ L247+ also had two new SNP results at Geno 2.0: he is F1915+ and YSC0000078+. These occur somewhere in the area of L277 or L247.