The thinnest 15-inch laptop "on the planet" is coming tomorrow, costing a measly $999, according to the Wall Street Journal. In a profile of Dell's recent history and forthcoming plans in the consumer electronics market, the financial paper twice makes reference to an ultrathin, $999 laptop that is set to launch on Tuesday of this week. Pairing that intel with the abundance of leaks surrounding the slinky 15.6-inch XPS 15z -- including a Michael Dell tweet promising it's "coming soon" -- leads us to the conclusion that we've finally