VG247 claims to have even more information on the release, stating that both the Blade Wolf and Jetstream Sam DLC will be included by default with the PC release. That's not too shocking, as Konami recently bundled the game's DLC in with its console version at a new $30 price point.
If you need further proof of the price drop, Steam's holiday sale currently offers the game at a $20 price point while also corroborating Amazon's January 9 release date. It fails to mention when Metal Gear Rising: Revengeance will begin to pre-load, but at least we the release date seems nailed down. Of course, if $20 is too still too pricey for you, you could take the advice of this CheapAssGamer forum post and score the game for $15 by using a coupon code at GameFly.