According to the Fight Network:
The pairing of two of Canada's top middleweights will be a 2005 rematch of an Ultimate Cage Wars 3 bout in Winnipeg, Manitoba in which Macdonald won via a fourth-round submission.
"If the UFC had offered for me to face anyone on that card, it would have been Jason, so I'm extremely happy with the match-up," said New Bothwell, Manitoba native Doerksen. "I wanted this fight for so long."
...
"[MacDonald's camp has] been saying that Jason controlled me for the whole fight, but I completely disagree. I have no problem with Jason. I don't think we'd be best of friends, but [MacDonald's manager Mark] Pavelich really bugs me," said Doerksen. "He rubs me like sandpaper. I want to go in there and beat MacDonald, and then I maybe I can shut him up. If I lose, then I'll accept it, and I won't talk about it anymore."
Decent match-up from a stylistic perspective as well as appealing to the hometown crowd with the inclusion of two more Canadians on the bill. I don't know that this match-up has any implications for the anemic middleweight division, but as a filler on the card this more than suffices.