This is somewhat down to cherry picking of data, I mean he chooses not to include MGS4... why? Well because it sold 4.8 million copies which is half way there to Halo 3's 11 million copies sold. though he is right, comparing just exclusive titles Microsoft has the SINGLE GAME that sold the most.
One thing I would add is: Why is this a bad thing?
I'd say the reason Halo 3 has sold 11 million copies is pretty much because Microsoft has put all their eggs in once basket, it is arguably true that Xbox 360 just does not have as many exclusives as PS3. They just don't have as MANY First party Studios.
One has to ask:
"How does one game selling 11 million copies indicate the SINGLE copy a user owns is any better? how does that make the wider console library more valuable"
For me with my Xbox 360, you play Halo 3 and then what? Xbox 360 has NO OTHER first-person-shooter games that they can call exclusive (OK, ODST, but that's virtually a stand alone expansion pack but with nerfed armour and attacks). 3 years from Halo 3 to Halo Reach is a long time to wait, the only other shooter the console can claim is Crackdown and Gears 2
OK, comparing just exclusives here, PS3 has more First Person Shooters:
Resistance (Fall of Man, 2) Killzone 2, with Killzone 3 and Resistance 3 on their way
They have more exclusive third-person shooter/platformers with:
Ratchet and Clank (Tools, Booty, Crack), Uncharted (Drake's Fortune, Among Thieves), Infamous, SOCOM Confrontation, MAG and Warhawk with Infamous 2 and SOCOM 4 (also maybe Uncharted 3) on the way.
Now I like my Xbox 360 and own a PS3 as well and sorry but looking at this objectively Xbox 360 just does not offer me as many games. Third party games like COD4 and GTA4 don't factor as you're better off getting them on PC. But for the multi-plat games that only see console releases I'll often prefer the PS3 version for the PSN's free online that I won't pay for any more and why should I pay for a service like Xbox Live which is infested with so many foul mouthed mic-abusers. It's worse than PS3 or PC or any other online. (yes I know PS3 may get a premium service, but it won't be necessary for online multiplayer)