As I understand it, McCain wants to lower everyone's taxes. The more you pay, the more you save. The richest people get the highest dollar amount cuts. I think that this is great, in that the people who are employing everyone else should get a bigger tax cut, thus freeing up money for higher wages, increased benefits, etc.
Obama, on the other hand, wants to cut the taxes for everyone except the wealthy, who he wants to tax MORE in order to make up for the lost revenue from cutting poor people's taxes. Of course, IMO, this most likely will have the opposite effect of McCain's tax cuts as now the rich people will cut back on expanding their businesses, etc.
So, I think it's technically correct that Obama wants to lower the taxes on MOST people, while McCain wants to lower the taxes on ALL people.