As Joseph has mentioned above, the Catalyst 6500 platform is still on road maps and just had a whole bunch of new hardware released, e.g. Sup-2T and line cards. Whilst it is no secret that the Nexus platform is what Cisco are selling people to go down the unified comms journey, the 6500 platform still has it's place within the data centre, especially as a services platform.
A recent (within last 12 months) example I can give you - I picked the 6500 platform for a large data centre network over the Nexus to provide 10GbE connectivity to huge amounts of server chassis with extremely high virtualisation ratios. Why? Because for this particular environment the Nexus platform couldn't meet all the business requirements, the 6500 could. Moral of the story? Use whatever product meets your business and technical requirements. There's no point asking a public forum "should I or shouldn't I" around any technology when you have provided no background information around those requirements.
Yes the Nexus platform has shiny features such as VDC, it also has some pretty big caveats depending on what you are doing - once again, back to what are your business and technical requirements?
As far as being crazy for considering a single N7k with dual sup's versus dual N7k's, it's no more crazy than not providing chassis redundancy using any other product. If you believe a single chassis can deliver to your business, technical AND availability requirements then sure, go for it.