Some interesting rumors have come up surrounding the return of the original Blue Bomber. These came from an individual known only as "SSJ4," who passed them on to blogger Protodude, who did receive tips about Mega Man 9 (aka Rockman 9) prior to its announcement. Nonetheless, get equipped with grains of salt:

Downloadable Content
"-DLC is intact for all three versions (Wii,XBLA,PSN).

-Access to DLC is on the Boss Select screen, bottom right corner.

-Capcom plans to upload new content every so often. Possibility DLC won't be available until two to three weeks after the game releases. (speaking of the game's release, Wii users can look forward towards the 22nd of this month...although they've discussed delaying it till the following week due to a BIG Virtual Console title that might take the attention away from RM9)

-Noteworthy DLC:
+Buster Shot Mods: Buster can fire different kinds of pellets such as a three way spread buster and a homing shot. No weapon energy used.

+Shooting Star Rockman: Rockman from the Shooting Star series is a playable character. Once downloaded, you can equip him in the Costume menu. (Japan only)

+Remixed Music: Download remixed BGMs, replaces 8-bit music.

+Title screens: Download new title screen images. One in particular, features Rock and friends "jumping for joy."

+Blues (Editor's Note: That's Proto Man, for the uninitiated): Yes, Blues is playable. Has his own set of moves/attacks. (Actually, he kinda sucks. Controls to loosely.)

+Auto messages: At some point in the game, Auto converses with Rock. This download changes what he talks about. One message featured Auto giving Rock his horoscope .

-DLC may or may not be "free." Capcom is considering options to make DLC redeemable. Wants to reward players for hard work.

-Plans a years worth of DLC.

Miscellaneous:
-RM9 was developed on Wii hardware, exclusive to Wii in Japan. XBLA Achievement are Capcom USA's doing. Not worth your time.

-RM9 was concieved as a brand new series, started out as a pet project at Inti.

-I've been told Capcom was fiddling around with two Rockman Wii titles prior to RM9's development, both have been shelved. Hiatus. (Scramble Battle?)

-RM9would not have existed without fan support. Future RM9 like titles will be fueled by fan support.

-I've played the XBLA and PSN versions, don't compare to Wii version controller wise. D-Pad on Xbox controller ruins the experience. PS3 D-pad is unresponsive. Wii remote controls are tight, perfect emulation of NES control.

-XBLA and PS3 versions felt like rushed ports of Wii version. Actually, they are merely ports. No touch ups." -- Protodude's Rockman Corner

It would suck if the Shooting Star, aka Star Force Mega Man costume were Japan-only; I have seen some pixel art around of that very thing when the E-tanks were announced.

The release date also fits with the rumored release date for the Xbox 360 version, while GoNintendo adds:

KingBroly tells us that in the latest Nintendo Voice Chat Podcast, the gang is talking about their embargoed Mega Man 9 review. Apparently, they cannot post it up until September 22nd. Hmmm…that lines up with a Monday perfectly! Just remember, we still need to get Mega Man 2 on VC. -- GoNintendo

It will be interesting to see what and how much of this pans out. The DLC sounds fun, at least.