There's a lot of misinformation in this thread, but i'm busy so I'll just respond quickly.
Subaru of America has allowed 7,500 intervals since mid-2011 MY.
http://drive.subaru.com/sum12_QuickStops.aspx
Yes, this is on 5W-30 and, as noted by others, the manual only refers to 5W-40 CONVENTIONAL for replenishment only. There is no such thing as 5W-40 conventional!!!
To those running Motul 5W-30, it is not API SN certified. IMO, this is a good thing but some people are afraid of not running SN oil. A dealer will not ask you if your oil is SN or not. Motul Eco-nergy is a thin 30 weight and is SL rated with a stronger anti-wear package.
X-clean is a thick 30 weight that meets Euro ACEA A3 specs like GC. It also has a nice shot of zinc and meets API SM specs.
Amsoil OE and XL lines are fully API SN / ILSAC GF5 certified.
Mobil1 5w-30 API SM shears from just shaking the bottle, but the API SN has shown decent uoa results in a WRX. Check bitog. There's just not much data on it.
Rotella T6 meets API SM specs for gasoline engines.
Royal Purple xW-30 API SM has been shown to shear like Mobil1 and EVERY other Energy Conserving 5W-30. RP High Performance Street is their good non-girly man oil.
Reflash your ECU or mod your car and your powertrain warranty is out the window anyway. Warranty schmarranty. Buy M1 5W-30 for the receipt and exchange it for M1 0W-40. Not that I condone this behavior.
To those that think one or two random $30 uoa's are useful in comparing wear between brands, this is not true.
http://www.bobistheoilguy.com/used-oil-analysis/
Note that the manual says that 5W-30 synthetic is required for "optimum engine performance", not that 5W-30 API SN is required for warranty coverage. BTW, there is no industry definition of synthetic. It is only a marketing term.
-Dennis