First, this graph is based on NPD. It doesn't include European figures, where both Uncharted and Gran Turismo 5 Prologue enjoyed the bulk of their sales.
Second, this is only because Sony has yet to release a title the caliber of Halo or Mario Kart. Their big game was MGS4, a third party title.
Killzone 2 and God of War III should help somewhat, but the major release is Gran Turismo 5, which will probably sell more than even Halo, thus increasing the attach rate dramatically.
So long as games sell enough to become profitable, we shouldn't be worried about this. The only thing is that some older titles like Lair might have never broken even, but the vast majority, like Uncharted, Ratchet & Clank, Resistance, and soon Resistance 2 and LittleBigPlanet, have been profitable, and the sales of Gran Turismo 5 Prologue have probably already covered all of GT5's development costs thus far.
The thing that's really hurting them are the games that have been in development for years that have yet to come out, like Killzone 2. During the first two years of the ps3's life, dozens of titles were being developed by Sony, with only a handful coming out each year to make back money spent. Starting soon, many of those titles that have been in development for a long time are finally being released (Killzone 2, InFamous, White Knight Chronicles), thus finally bringing Sony a return on their investment.
Unless you think all of these games will flop, i wouldn't be too worried about it.
