This is about McGraw-Hill (MHP), the information services company whose units include credit rating agency Standard & Poor’s. You know, the same S&P that may or may not be fixing to downgrade America’s credit rating from AAA to AA. Or the same S&P that did stamp AAA on shoddy sub-prime mortgage bundles, thus facilitating our debt crisis in the first place. It’s kind of like the bully who smacks you in the nose, and then hits you even harder for bleeding.

McGraw-Hill’s shares are up more than 9% today, after hedge fund Jana Partners disclosed a 2.9% position and said that it had recently met with company management to discuss “business, corporate structure, operations, management, Board composition, and strategy.” Traders seem to believe that’s code for break-up, particularly since Jana seems to be working with Ontario Teachers’ Pension Plan, which today disclosed its own 2.3% stake.

Those positions may not sound too large, but Jana and OTPP combined are now McGraw-Hill’s second-largest shareholder behind Capital World Investors (12.45% stake). Individually, Jana now ranks seventh while OTPP ranks tenth.

McGraw-Hill publicly acknowledges that it is “conducting a comprehensive portfolio review” that should result in “significant actions” this year, but the relevant significance will be in the eye of Jana and OTPP.

Conventional wisdom has been that McGraw-Hill would sell off some smaller content brands like Aviation Week and J.D. Power (Businessweek is long gone, sold in a 2009 fire-sale to Bloomberg). But now there are questions if S&P also could be on the block, or at least spun off into an independent company. After all, S&P could generate cash via an independent IPO while retaining partial ownership upside.

In a research note, however, J.P. Morgan downplays the possibility:

A push to unlock value at McGraw-Hill isn’t a new development. Several times over the past 20+ years, there’s been talk of potentially significant corporate action (most recently in 2006, when Barrons stoked the flames with a “Free S&P” write-up). Such conversations typically revolve around a potential spin of S&P Ratings (47% of MHP profits) and/or M-H Financial (20% via Indexes, Capital IQ, etc.). But those businesses are among McGraw-Hill’s best and we don’t see the logic in divesting either—as they have 1) nice secular tailwinds (globalization, bank disintermediation, etc.), 2) high margins (46% and 27%, respectively), and 3) global footprints (49% and 31%). They also share the S&P brand, and have inter-segment relationships around the credit research “product.”

Instead, J.P. Morgan believes the target segment is Education — 22% of MHP profits, compared to just 10% for Media — which includes  such brands as Macmillan. The unit’s valuation was around $3.3 billion before the activist bump, which could make it an affordable M&A target for either strategic or private equity buyers.

McGraw-Hill stock was trading at around $45 per share as of this writing. J.P. Morgan has a target price of $46, but says the sum of its parts could push the price past $50. Lazard reportedly believes that the break-up value could approach $60 per share.