This can already be achieved with Flic: http://flic.io Flic is a Bluetooth button which uses your smartphone to communicate with smart electronics. If you have Philips Hue or LIFX smart lights and a Logitech Harmony Hub (for IR), this would work straight out of the box! (Disclaimer: I am associated with Flic)
I'd also be interested in this. Would love such a button that could connect via WiFi or generic BT on a Raspberry Pi or something like that, rather than a smartphone with a specific app.