That's an awesome theory, and I very much like the idea that the device that people a month ago were speaking about in hushed tones as the next amazing leap forward("ZOMG LOOK AT THOSE STATS") and the device that those same people are now poo-pooing("lmao 800mhz FAIL derp") are one in the same. Oh, what delicious irony THAT would be <3
However, there is some evidence to the contrary.
1) GLBenchmark, the site that had the numbers that were reported for the Glacier, lists the Glacier and the Vision as separate devices. (http://www.glbenchmark.com/compare.jsp
... use the drop-down selection boxes)
2) It's fairly well-established that the Vision is the G2. (compare these pictures: http://www.tmonews.com/2010/07/htc-vision-is-viewed/
to these pictures: http://www.tmonews.com/2010/08/and-just-like-that-the-g2-in-the-wild/
3) The numbers posted for the Glacier(http://www.androidguys.com/2010/08/04/htc-glacier-tied-project-emerald/emerald_glacier/
) are different from the ones posted for the Vision(http://www.glbenchmark.com/phonedetails.jsp?D=HTC%20Vision
) ... look at the Pro ES 1.1 CPU Skinning benchmark, Glacier is 1432 vs. the Vision's 1370. Not a big difference, but a difference.
Not to say that you're definitely wrong, but you asked for evidence to the contrary and I provided. Of course, this is all speculation and there's no guaranteeing the reliability of the GLBenchmark numbers anyway. Who knows, maybe the Glacier is just an earlier codename for the Vision and the difference in numbers is from different prototypes.
But yeah, it would be cool if you're right. Either way, I'm snagging the G2 up just as soon as I can.