i still feel that ghost is currently better than flash on all but a few characters (like fiddles or other AOE ult characters), but the nerf to flash actually makes fiddles, annie and other stronger since people can't just flash away from cacaw or tibbers anymore. it hurts characters like leb and shaco who rely on that gap-closing speed to cross huge distances quickly, but characters like amumu, nunu, and galio still get the OSHI- benefits of extra positioning from it without totally getting rid of it.
i am looking forward to the boost to cleanse, though, and i'll be using it a LOT more, especially on characters like malph. it's almost a must for junglers with no gap closing, though - how do you shut down an udyr or xin? you exhaust them. this prevents that basically every time.
i also look forward to 'surge' and promote, both of which will likely become awesome 1v2 lane buffs. i doubt anyone would bring both, but i can see it being very effective early, and with pushing lanes.