watch os 2 gm

i could be wrong but it should be the same version, GM will be the version that gets released next week.

i knw that gm is same as final but will i be able to update to further verions from watchos 2 gm?

The build number of watchOS 2.0 GM is 13S343. You will only be offered an update if the build number of the final release is higher than this. The 13S won't change but, if the build is improved on before final release, then the 343 will be incremented and this will trigger an "Available Ipdate" via the Watch App. If not, there won't be a way to update past the GM because it will be identical to the final release version.

As for betas and release versions of watchOS 2.1 (or maybe Apple will go the 2.0.1 route instead) and higher, then yes - there's nothing to stop the watch updating to these from the 2.0 GM.

-Max.

I've tried to further clarify the situation in the accepted answer above, in case it's of interest.