Even if the HST is not revenue neutral, which I believe it wont be, it is still a good, modern and progressive tax. One tax instead of 2 means less bureaucracy, less accounting. Yes we will be paying more for gas, and condo fees, but we will save money on income taxes and get more tax credits for the HST. So overall, as someone pointed out, you may be down slightly if you earn a certain income level or up slightly if you're low income. At the end of the day, it's a consumption tax, thus it can be avoided (unlike income tax). One can reduce their gas usage (get a more efficient vehicle, carpool, chain your trips, take transit), one can reduce electricity usage (condo/utility fees go down), etc..
Remember folks, the HST is meant to save and spur new manufacturing jobs because manufacturing jobs generally pay well (new income earners ==> more taxes to gov't), and create spin-off service jobs.