I'll post some stats and facts later for people to anaylze better but what do you think?

Nooooo.

hmm, difficult to say. GT 6's sales will be affected by the PS4's launch. Also GT6 doesn't sell as quickly as Halo but has better legs. I'm gonna say no.

i dont think so

Both games are going to get cut short with Next-gen coming unless GT6 gets released on PS4 as well or the NeXbox is bacwards compatable. Most likely no. Halo sells much faster than Gran Turismo and it has decent legs to push it forth. They may end close to the same but it will take GT much longer to reach those numbers.

I did say that they will likely end up near each other.  it will just take GT6 much longer to get there than Halo 4 did.  

If gt6 releases on ps4 aswell then It will win otherwise probably not.

yes, if GT6 has a ps4 version down the line.

Despite Halo 4 not having the legs the franchise deserves, It will sell better. 

After the disappointing reception of GT5, people know there are superior racers on the market. Also, this late in the gen, I don't think the franchise will open as big as GT5.

Lastly, despite PS3 selling the best, there is no indication of games selling better, unless bundles are involved ie Uncharted 3. Its pretty clear PS3 owners are cross Europe are mainly buying PS3's for FIFA and COD as multiplatform games are generally still selling better on the 360. 

We'll never really know unless we get full retail + DD numbers for Halo 4 from Microsoft, but I don't think it's likely. For all this talk about legs people seem to forget that Halo 3 is still choofing along, doing more units than plenty 2011/2012 titles.