From an Australian perspective... (i.e. one who cannot go to the shops and purchase mixtapes... one who must kick and scratch to find poorly recorded mp3's of pirate radio sets)
IMO, Grime artists should make a conscious effort to release their best material on albums. It WILL sell. Dizzee has proven this. There is a market out there. Folks in my neighbourhood were expecting the grime equivalent to Enter The 36 Chambers from Roll Deep. It ain't gonna happen, it just won't happen. For whatever reason, the folks in the grime scene believe that selling product means releasing the most commercial of tracks. To foster a real worldwide SCENE, you need exemplary albums. Boy In Da Corner is one. Wiley's album is almost there.
I've heard sidewinder mixtapes where wiley is spitting intoxicatingly fluently. His album doesn't match (what do you call it is easliy the standout track though.) In fact, almost every rinse (or otherwise) set I hear involving Wiley is more cutting edge than his album. This is the music people want to hear. If you sell to the lowest commmon denominator, the lowest common denominator will determine the future of the scene. That's bad news. There are hundreds of thousands of people out there waiting to taste a bit of REAL grime. It's very hard to find when you're outside of the UK.
Call me a cynic, but i think there is more of a market for the "underground" sound than the commercial grime sound. "Commerical grime" won't make sense to anyone outside the UK who hasn't really experienced garage, jungle and dancehall records. Shake A Leg is good, but it's still just a looped sample with a bunch of mc's spitting amusing lyrics - almost an in-joke. If it does really well in the charts, it won't say anything about the actual scene.
UK Grime, eski, sublow, dubstep, 8 bar, dark garage, whatever you call it, is the most exciting music I've heard my whole life. It deserves a wider audience; and I don't like people selling it short. There's amazing talent out there, and so far it's not been exposed to the outside world. Dizzee Rascal has taken one step - who will take the next?