I want to thank Chad for his work here and report back some of my technical data I have been able gather while testing. This was gathered with electrical test equipment and is accurate unlike the current widgets.
For the Touchstone Mod users:
Prior to Chad's kernel modification the Galaxy Nexus was only able to draw ~430 mA through the Touchstone. For some power users, this was not enough to keep up with heavy usage that included Navigation, 4G, and streaming music simultaneously. Reports had the phone either just barely maintaining its charge % or even slowly losing a couple % points per hour.
After applying Chad's kernel modification the Galaxy Nexus is drawing ~650 mA. An improvement of ~50%! Now the bad news: 650 mA is not as much as you can get from an appropriate wall charger. The limitation at 650 mA appears, in my opinion, to be the Touchstone itself. The Touchstone's supply voltage drops to 4.5V when drawing ~650 mA and the phone stops trying to pull more. This is a limitation of the amount of energy the Touchstone was designed to transfer.
The real question, is if 650 mA is enough to charge the device under the power user conditions I described earlier. Hopefully it is. I do not live in a 4G area so I hope you will all test and report back here.
Thanks again Chad!
For everyone else as well:
To everybody unfamiliar, unless there some undocumented functions to directly read charging current there is no accurate way to read current from apps or widgets. They all make estimates that are only at best, ball park good and only when looking at a long enough time period. Seriously, you won't get within 300 mA. The only way to accurately measure charging current currently (to the best of my knowledge) is to make physical measurements using test equipment such as a multimeter with an ammeter. The current you actually pull from any source will likely fluctuate depending on the limit of current the source is rated for ( and even then, the actual numbers will probably be quite different) and the voltage the source can maintain while supplying that rated current. Do us a favor and don't post the currents your widgets and apps are reporting... they are not accurate and provide little to no information. They may let you see that you are in fact drawing more current than you used to on "USB mode" but that is about it.