Walt Mossberg is running a sneak peak look at Lenovo’s ThinkPad X300, which will obviously be compared to Apple’s MacBook Air in the war of the ultra portables. Like the Air it comes with a 13 inch screen (This still amazes me. I would think a 12 inch screen is perfect for these devices, but that’s just me.) Unlike the Air, it comes with a built in optical drive, removable battery, a bevy of ports-including Ethernet. It can also be ordered with an built in cellphone modem or GPS. Other differences include the starting price (betwen $2500 and $2800) and that it will only be available with a 64GB SSD. No hard drive options here.