rk911 is absolutely correct. Those new smaller antennas pick up nothing but radio waves, just like those old rabbit ears do. What information is carried on those radio waves, whether analog or digital is irrelevant to the antenna.
The changes that theoldwizard1 referred to are the broadcast channel changes that have already begun as part of an FCC mandated shrinking of the TV broadcast frequency spectrum, allowing more room for other wireless services. If you are purchasing a new antenna, make very sure it's capable of receiving both the low and high VHF channels, as well as UHF, since a number of stations are moving from UHF to VHF, including the low 2-6 channels. Some OTA antennas, such as the King RV units, are not very good for VHF reception, particularly the lowest channels.