Hi there, I just signed up on this forum.
I just saw Bosch has announced a 6.3 Ah 18V (20Vmax) battery. Their current highest capacity option is 6.0 Ah. The new battery will be named Bosch GBA 18 V 6.3 Ah EneRacer Professional.
Bosch was the first power tool company to come out with a 6.0 Ah battery last year.
Just like Bosch, Metabo is also a front-runner in bringing out the highest capacity power tool battery packs and is the current 18 V fat pack leader with 6.2 Ah. Milwaukee also has an 18 V; 9.0 Ah "mega fat" battery pack, but that is with 5s3p cells instead of the usual 5s2p cell configuration used in all regular 18 V fat packs. 18 V slim packs use a 5s1p cell configuration.
Toolguyd article including video demo from the Bosch Blue Innovation Summit 2016:
http://toolguyd.com/bosch-connected-18v-cordless-power-tools/#comment-801003
Press release - Bosch Power Tools relies on connectivity:
http://www.bosch-presse.de/presseforum/details.htm?txtID=7664&tk_id=112&locale=en