If the lockout of 2012 stretches into 2013 without Stanley Cup playoffs the Toronto Maple Leafs would finish the non-season near double figures in a dubious category. No NHL during 2012-13 would see the Leafs go 9 straight years without the postseason.
Nine consecutive years, not seasons but years, without postseason would be a record for the franchise. Two of those years of course would be due to a lockout so the official streak would remain at 7 seasons of failing to qualify for the postseason. That too, and by a long ways, is a franchise record.
The Toronto franchise joined the league as the Toronto Arenas at its inception in the 1917-18 season, changed to the Toronto St. Patricks in the 1919-20 season and then became the Toronto Maple Leafs in 1926. The franchise had previously gone just three seasons straight with no playoffs, the first, in '25-26 as the St. Pats, the next two as the Leafs.
Maple Leafs and postseason
So it wasn't always bad, in fact prior to this current streak beginning with the 2004-05 lockout, in 71 years under the name of the Maple Leafs, Toronto had been without postseason NHL hockey just 18 times. By contrast in those same 71 years, the New York Rangers, who came into the NHL the same year Toronto became the Maple Leafs, missed the postseason 30 times.
The Florida Panthers have the longest postseason consecutive drought in league history with 10 straight seasons with no postseason, from 2000-2001 until last season (11 years with the 2004-05 lockout). The Maple Leafs have the longest current drought without making the Stanley Cup finals; the last time they won the Cup, in 1966-67, was the last time they played in the Final. That's 45 years ago - and counting.
And finally for a little perspective, when the city of Toronto last saw Stanley Cup playoff hockey Brian Leetch, Aki Berg, Ron Francis and Drake Berehowsky were still members of the Leafs, the Montreal Expos were still the Montreal Expos and Leafs fan Justin Bieber was 9-years-old.