I am Laz, tested R1b
We will make haplotypes public some time in January/February 2013. Meanwhile I can tell you that many of them are Caucasus cluster G2a1a1
I am of Laz ancestry, and recently tested R1b haplogroup. You are correct about the Mergel association. Turkey is very ethnically diverse in general- the area has many different 'tribes', they named everyone from Samsun to the east of the Country in the black sea region 'Laz' but not all of that population is 'Laz.' The name 'Laz' was a nickname given to this population by the ottomans. We consider the people who speak Laz language, which is very similar to Georgian and the same as Mergel language, to be Lazuri. The language is about 10% greek. We use the same city and town names as are used in Greek. The people who speak Laz/Mergel in Turkey are mostly concentrated from Ardasan to Sarpi.
Another population of Laz/Mergel speaking people exists in Russia. These people were unaware of a differentiation between Laz and Mergel.
In Sarp, where I am from, there is a wide variety of people. There are people who look very Irish, however my family with the R1b haplotype are not amung them. There are blonde people, redheads, freckles and blue eyes, as well as people who look more Greek or Turkish. We live next to the Black Sea, and about 5 miles inland is a population called Hamsin, who speak Armenian. That population, which lives within the Laz speaking area, has never really intermarried with Laz people until recently.
I would love to hear about other Laz genetics or any information which is available. I am no expert, but this is my understanding from having interest in this subject and searching as well as the knowledge I had while growing up.