I agree with Victor - one of the concerns with a high GMAT low GPA combination is that adcom may conclude "smart but lazy".
Adcom aren't evaluating your GPA on the basis of numbers, but they are going to be concerned about whether you are going to apply yourself to your studies fully at Wharton, when there is some evidence that you haven't always in the past.
However, adcom are aware that people mature over time, and that past performance is not always a perfect predictor of your capabilities now.
It may be worthwhile to help adcom understand what was going on, but honestly, when it comes to 'explanations', talk is cheap, and an explanation accompanied by positive evidence of your capabilities now will go a lot further than an explanation alone.
Probably the best thing you can do at this stage is to build an alternative transcript, by taking some additional classes and doing well in them.
Adcom will also probably be looking at your track record of applying yourself to achieve professional success, and perhaps the general sense of maturity that emerges from your application.
FF (who was admitted to Wharton with a GPA of around 2.6)