Re: Ex-Box One, next up according to financial analysts
http://arstechnica.com/gaming/2015/04/xbox-one-slowly-narrows-its-quarterly-sales-deficit-against-the-ps4/
says "The usual disclaimer about sales vs. shipments here... while the two numbers aren't precisely equivalent, hardware units shipped to stores are usually sold through to consumers in four to six weeks, according to industry analysts. So most units shipped by the end of March have likely been cleared off of store shelves by this point, having little impact on the relative console race. The terms are used interchangeably throughout this piece"
IF that is the case, then as you say ("3:1") MS have about 1/4 of the current console market sales.