General Data Flow:

Internet (ie IFTTT) > Host > Processing Sketch > USB > RF-TX >> RF-RX > Display

Detail 1: nRF24L01's have a nice little 32 byte payload; use byte 00 as a channel ID number, leaving lots for message space. The receiver units can then be 'tuned' to display (or cycle thru) certain channel #'s, or ignore others. Other channel #'s can be marked as priority/cut-thru, so things like weather alerts or any important message like 'hey there is water in the basement!' still appear as soon as they are RX'd. This also means that RX units can use any alert method for one or more channels; audio, colored LED's, alphanumeric scrollers, LCD / TFT panels, or full on HDMI displays.

Detail 2: The base sending unit (for rev 1.0) is just a simple USB connected Arduino driving the transmitting radio. A Processing sketch performs the heavy lifting of pulling in external data, massaging it, and transmitting any relevant info out to the slave units. This means that the config only needs to be done/maintained once. Rev 2.0 could be it's own WiFi enabled device, translating data on it's own without Processing or host computer, so the configuration format should be fairly portable and lightweight. Rev 3.0 would move to public / private cloud configuration, and WiFi would replace RF for receiver units within WiFi range, removing the need for a central hub device completely.