Canon has not given any specific indication what their target might be for a higher-resolution full frame or medium format camera. Unless I am mistaken, the "10,000s of customers" line is not in the original.
Since 10,000 is plural, we'll use 20,000 for the short end.
For the love of...
"How many (including 1 x) 10,000s" seems perfectly acceptable, especially in Japanese.
However, the line of the original translation does not read that way. Here are the relevant couple of lines from the original:
I don't see any mention of an actual targeted number. For "10,000s" you would expect to see the character 万 somewhere.
"However, in the early to talk about specific plans at this time, but research has naturally. Ultimately assess the market demand, I will go and whether we will reach a camera such as Canon do."
"It isn't in the stage which can speak about a clear plan in the present, but it's being studied of course. I think request from a market will be ascertained finally, and thinks what kind of camera to take out from now on and goes as Canon."
On Keith Cooper's Google+ translation line, a Mr. Ellis Vener has offered a "rough translation." It is there that the "10,000s of customers" line originates. I believe this is just his opinion of their likely business strategy, similar to how I often write what I think Canon is doing or ought to be, but usually I do not put my own words in their mouth.