After playing in just about every 3's event on US, from a player perspective 3s is getting really old. I think a swap to have a 2v2 tournament would be extremely beneficial for multiple reasons.
1. People actually play 2s on a daily basis, not to say you can't organize 3v3 wargames but that really has only happened once in a blue moon, usually preceeding some form of 3v3 event. We haven't actually had a tournament for the arena bracket that pops on a daily basis that people are more familiar with.
2. Having a tournament for the 2v2 bracket will encourage teams to queue up pugs arenas and try out their comps, making the 2v2 scene more competitive on a daily basis as people narrow down the specific combination they want to run.
3. There are more viable comps that you can run in 2s than you can in 3s, which to a lot of people may not make sense. In 3s teams pretty much have run rsham/melee/melee or disc/bm/mage with success, there are a few comps out there that can challenge said teams, but it is extremely limited. You can always adjust 3v3 rules to encourage new comps, i think regardless of rule restrictions classes such as rogue and paladin (minus stubs ret dream) become taken out of the equation of 3s, where as both those classes in my opinion could have better looks in 2v2 bracket. 2v2 bracket burst is down from 3v3 for obvious reasons lacking that third player slot, with that in mind it opens up teams to run double hybrid comps rather than a healer, there is even a handful of comps that are viable that have no built in healing.
4. Finally you will see more people play in the 2s tournament for reasons mentioned above, can queue and practice every day in pugs, more comps can work in 2s, and the real kicker is that you only need a partner to play.
TL;DR Give 2v2 a shot