I would try to acquire Paizo. Then I would put Paizo in charge of D&D, with instructions to maintain two lines, D&D Classic (mostly Pathfinder, but with more traditional art) and D&D Modern (4E's direction, with more mandate to change the system ).
I'd give Lisa Stevens full authority to hire and fire staff across the entire product line. And I'd hope that she'd try to rehire Monte Cook and Johnathan Tweet.
I would keep DDI , and expand it to accomodate both product lines.
1) Find someone actually qualified for the job to do the real work of the WotC CEO.
2) Spend all my time with D&DI group where I actually know what I'm doing.
For D&D, I'd put Chris Pramas in charge and have Steve Kenson rework 3.x Some things I would want changed included toning down the spellcasters, rework multiclassing and incorporating some elements of both Unearthed Arcana and the three Master Class series books that Steve wrote. PrCs would also be down played or eliminated while customizing a character through class variants would become prominent.
For d20 Modern, I'd hire Charles Rice to rework some elements (e.g., talents, occupations, action points, automatic weapons, martial arts, magic fix) and incorporate Green Ronin's Psychic's Handbook for mental fx. I'd also want to reduce or eliminate advanced classes and move many of the abilities into talent trees.
I would actually see if I could reintroduce Duelmasters in the N.American market.
Duelmasters is a smash hit in SE Asia and apparently has overtaken both Yugi-Oh and Pokemon in popularity there....Sure, it failed once, but give it another go.
I'd also put the POLYHEDRON flipside back in the DUNGEON Magazine PDF, still in backwards order and upside down, then watch the hilarity ensue as hundreds of threads with thousands of posts filled with nerd rage start appearing about it on the rpg message board rounds, until some of my loyal Rouseketeers suggest you're just doing it wrong and not long enough as you just have to flip your monitor over to read it.