According to Ars Technica, unnamed sources have revealed that Final Fantasy XIII and Splinter Cell: Conviction bundles will be coming to the Xbox 360. Apparently the bundles will come with a 250GB hard drive and a price tag of $399.99 USD. The only difference between each bundle, besides the game included, will be that the Final Fantasy bundle comes with two white controllers whereas Splinter Cell comes with black ones.
This rumor has a little bit more credibility than most because it was revealed by the same people who broke the PS3 Slim and Resident Evil 5 bundle stories last year. Ars Technica goes on to say that these bundles won't have any unique branding and are being called 'Special Edition' bundles, so there is a possibility that a small number will be produced. No word on whether Sony is working on their own Final Fantasy XIII bundle for PS3.
If the source is correct, the Final Fantasy and Splinter Cell bundles will be released on March 9th and April 13th respectively.
Source: Ars Technica