That article illustrates exactly why we'll never have a sales tax in Alberta; that's not how it took place! In fact, Gosbee and Mintz both laid out plans for a consumption tax to take the place of income tax and not to add to what Albertans pay. Mintz was very specific and said we could have a consumption tax of about 8% and have income tax cut at about 4% or increase the exemption in Alberta to about $60k.
In 2000 there was a report written when he (Mintz) was with the CD Howe Institute and the authors suggested the rate could be at 6.25% and virtually replace income taxes altogether. Mintz was specific yesterday though, in that this would be revenue neutral and was a structural change.
Gosbee pointed to Texas having that 6.25% rate and having no income tax and because of this being able to diversify and stabilize its revenue stream. Years ago they were reliant on resource revenue as well (I think he said 23% of their budget) and today they've drastically reduced that reliance.
Anyway, point is that articles like this don't do what took place yesterday any justice. There was a huge amount of information there and I did my best to summarize here if anyone is interested.
http://victorlough.com/?p=255
(Hopefully that link works, but if not I'll fix it!)