Chalk this one up under the 'lame' category: looks like the T-Mobile G2's CPU ticks along at just 800 MHz. In a world of 1+ GHz smart phones, that's definitely something of a letdown.
A slower clock speed doesn't always equate to lesser performance - but without any solid previous benchmarks to illustrate what this new(er) CPU is really capable of, it's hard to say whether this is going to be nearly as adequate as T-Mobile claims.
In hindsight, the fact that the G2 is a HSPA+ device could have been something of a giveaway as to the underlying hardware - check out this piece from February 2009 that states that the Scorpion CPU will integrate CPU and GPU functionality, as well as HSPA+.
Looks like we'll just have to wait a few more weeks to see just how much of a monster (or not) the G2 ends up being. If nothing else, the dev community should be able to whip something up to improve performance.