Ready to have your mind blown? XM and Sirius never merged in Canada. Even after the two companies joined forces in the United States, they continued to operate as separate entities north of the border, with XM Canada wholly owned by Canadian Satellite Radio Holdings, while Sirius Canada operated through a partnership of CBC Radio, Slaight Communications, and Sirius XM in the US. That's now finally set to change, however, with the two companies today announcing plans to merge in an all-stock deal valued at $520 million (including $120 million in long-term debt). Assuming the deal is approved by the CRTC, the combined company would boast a total user base of 1.7 million, and Canadian Satellite Radio chairman John Bitove promises that the new entity will deliver an "exceptional value to subscribers."