At what point should one re-enter shorting this thing?
Take your cues from the S&P.....Yesterday indicated sellers took control of the market for the first time since early January. There is a potential for the S&P to fall back into the 1465-1475 level. You will see put buying (volatility) increase as the selling persists (if it persists). Look to close longs, or get short with an increase in volume near those levels on the S&P. Hard to say where VXX could be, I would expect the actual VIX index to get into the 20 range if in fact the S&P falls into corrective territory, which would be the long term average for the index and perfect place to sell any thing related to volatility.