The MSP-EXP430F5529LP launchpad only has one USB port but it has two USB devices on board. It uses a TUSB2046, which is a USB hub, to allow the PC to connect to both devices (the debugger and the MSP430F5529's USB port). Perhaps it would be possible to "turn it around" and have the single USB upstream port connected to the microcontroller. (Not on the kit board, obviously, but in a project.)
In other words, maybe you can use a hub? If you want a dev kit where the chip as its own dedicated usb port, the EFM32 kits from Silicon labs have that (e.g. EFM32LG-STK3600 or EFM32GG-STK3700). The second USB port is used for debugging. I'm not sure of the possibility of coding the use a hub, though.
Edit: From Silicon Lab application note AN0801: "The EFM32 USB Host Stack does not support hubs."
Another edit: It looks like MSP430 USB-enabled chips can only be a "device" and not a "host".
Edit 3: TI's TivaC series of chips may allow a hub to connect when it's acting as a host. See "TivaWare USB Library for C Series User's Guide"
http://www.ti.com/lit/pdf/spmu297 Section 3.4.2 "Hub Class Driver"