Dehaka's a lot of fun. Muradin Dwarf Toss into the enemy team, when you know you damn well shouldn't, just to Haymaker someone in to yours fun. Like Chen kick, keg smash, fire breathe, chug and repeat someone to death while they can't chip away at your shields fast enough fun. Dehaka looks so damned boring, his kit is so understated but he's so much fun. Global mobility, a great stun, great sustain provided you farm enough essence, it feels like there's a lot of choice at every talent level, I just don't know about both of his ults because I've been taking Isolation every game. I've only played a handful of live games but so far he's great at shutting down Li-Ming. Granted I've been playing against some seriously aggressive ones and with teams that didn't seem to respect the drag or react fast enough to save her, but with the ability damage reduction talent, essence healing you and Isolation you can get close enough, silence her to shut down her bullshit laser and maybe drag her to her death.
His one real weakness, aside from being someone you can bully at range (holy fuck Raynor) and that he lacks damage, is that his one CC reduction ability is tied to his AoE being active whereas most other CC reduction abilities are passives with a CD that just proc when you're CC'd. Smart players wait out the AoE for the full effect. You can dodge a lot with burrow though provided you don't get stun locked.
He's a fun warrior to play as, dunno how viable he'll be in the long run, but I can see myself playing Dehaka as much as I do Muradin.
I wonder how long it will take for some people to try and add Dehaka to the Zag/Nydus, Aba/Clone cheese.