Guild Wars 2

http://metabattle.com/wiki/Build:Mesmer_-_S/S_/F_/P

This build only uses an offhand weapon in the second weapon set.

Using only an offhand, means you have your leap and blurred frenzy sharing with your second weapon set. Mindslash already has no cd, so you only get 2 new spells when you swap weapons.

Are there great pve builds who use 2 full weapon sets?

Yashuoa.9527:

Are there great pve builds who use 2 full weapon sets?

Not really. The autoattack from mainhand sword does significantly more damage than anything else. Additionally, there are no other mainhand weapons or sets that provide good utility needed in dungeons in the first three skills.

I would reccommend picking up an extra main hand weapon for two full sets if only for the extra sigil slot

Fay.2357:

Yashuoa.9527:

Are there great pve builds who use 2 full weapon sets?

Not really. The autoattack from mainhand sword does significantly more damage than anything else. Additionally, there are no other mainhand weapons or sets that provide good utility needed in dungeons in the first three skills.

Will this change when HoT is released and with the Chronomancer?
Is that already known?
Or will sword still be used in both mainhand weapon swaps?

Unfortunately HoT will only give us offhand shield, so double sword sets will still be dominating PvE.