What keeps XLR connections in demand is their ability to help move a balanced audio signal--two signal lines and a ground--over great distances and prevent unwanted noise.
Consumer electronics and the connectors they employ--RCA and 1/8-inch mini plugs--typically move unbalanced signal lines. With the lines blurring between consumer and pro electronics, adapters are an option for moving balanced signals. Plus, the form in which the adapter appears has also been updated.
A common form is an XLR female (3 holes) to 1/4-inch TRS male connector--ideal for plugging a microphone cable into a 1/4-inch input of an effect unit or recording device. Similarly, a 1/4-inch TRS female to XLR male connector is suited for plugging directly into a stage connector or snake box from a guitar or effect processor.
Adapter "boxes" are also available. Similar in size to a four-channel audio mixer, this type of adapter accepts numerous types of connections and converts unbalanced signals into balanced signals, creating a wealth of uses ideal for home audio and video applications.
Those hoping to find XLR adapters in the big box chains will have to wait. However, the online market appears to have a firm grasp on the value of a balanced signal and what tools a consumer needs to harness it.