It's a very good deal and smart move.
Lets remember something: At this time last year, MS was selling 1,200 units to 2,000 units every week. Now the are moving 2,900-4,000 units every week. MS had the best Christmas ever thanks to Blue Dragon and Lost Planet. Did they save the system? No, of course not. But for comparison, they did more than almost any other game in history to atleast help out a system.
The BD Bundle helped move around 50,000 Xbox 360s. A small number compared to what the Wii moves every month, but for MS that was nearly 10% of the entire Xbox's original lifetime sales in just a few weeks....This doesn't include the sales in November (a major increase) or January.
Look at my lil avatar for proof. The 360 is about 40,000 units ahead of the 360 at this point and time last year. Last year was MS's best year in Japan. Does that matter to Sony or Nintendo? No, but it matters to Microsoft. The 360 could see a 200% increase in h/w sales. MS thinks its a good proposition to do what they are to get to that point.
IMO, Trusty Bell pack *could* let the 360 see an actual week or two above the PS3. I anticipate Trusty Bell to do 75k to 110k lifetime sales in Japan. The pack could allow for 30,000 h/w sold or more. Again, not much to the Wii giant, but again, it'll allow the 360 to have a "stellar" year compared to any other year. Heck, between TB and Lost Odyssey, the 360 has an outside shot of selling MORE units this year than the Xbox did in it's ENTIRE LIFE. By the end of this year, the 360 will already of beat the Xbox's total sales in just 2 years. That's pretty good. It's not like MS having succuess in Japan means anything to Sony or Nintendo, but to MS, it allows a 3rd front to atleast garner some J-Dev support that they so rarely have now.
Again, one who doubts that a good JRPG title, or any J-game whatsever can move software only need look at Rumble Roses, N3, Dead Rising, DOAX2, Lost Planet, Blue Dragon, Enchant Arms, and DOA 4. All of these systems boosted sales by quite a bit. Alot compared to the PS3/Wii? No, but to MS they know that it's helping out a bit each time. Why? Every h/w unit the Trusty Bell pack sells will garner about 2 other s/w titles bought in the near future from those purchases. This will help out the other games coming out near the same time.