I for one do not want to see Brock/Taker.
Not only is it something we've seen before (albeit not Deadman Taker), but it's increasingly dangerous for Taker to get in the ring.
I remember in the Mania of Wrestlemania documentary, where Kurt Angle was talking about going into his main event match against Brock Lesnar with a seriously broken neck.
He says he'd much rather be in there with a ring general like Triple H who knows his limits and can protect Angle, rather than someone like Lesnar who works stiff and doesn't know his own strength. Funnily enough, Brock ending up being the one getting hurt by Brock, not Angle.
And that was a Brock Lesnar who had wrestled non stop since debuting a year earlier and training for wrestling in OVW non stop before that. The Brock Lesnar who would potentially face Taker at Wrestlemania is not the same man. He's rusty in the ring, needs stipulations to cover it up, makes sporadic appearances and wrestles maybe 2 or 3 times a year.
He could seriously hurt Taker, who will be weaker than ever before. Sure, that makes for a great storyline, but the reality is actually quite worrying.
Put Brock against someone he hasn't faced in a main event feud like Taker. There are plenty of options. He's never had a program with Orton. See, I just came up with that in 10 seconds. A hot Orton vs Lesnar would sell massively, and wouldn't have the possible manslaughter of Mark Calloway hanging over it.