The user manual for the Verizon Wireless Home Phone Connect states that you can use your existing telephone answering machine instead of Verizon voice mail (page 14). It appears that Verizon Home Phone Connect handles the end of a call different than a traditional analog line which may confuse your answering machine. With a traditional analog phone line, there is a short electrical signal indicating that the caller hung up their phone and the call ended (which you hear as a click). Verizon Wireless Home Phone Connect does not appear to issue this electrical signal, but instead puts a busy signal on the line. While a person knows that the call has ended when they hear the busy signal, my older answering machine does not recognize this as the end of a call and continues recording the busy signal following the message.
I believe this electrical signal that I mentioned is part of "CPC signaling".
(For reference, my answering machine is a Meridian M9516.)
So it seems to depend on your answering machine - if it requires the traditional electrical signal at the end of a call, it effectively may not work with Verizon Wireless Home Connect.
If I've stated something incorrectly, please correct me. Othwerwise, be aware of this difference in service if you are looking to replace your traditional analog line with Verizon Wireless Home Connect.
Just some more information.
I purchased the Home Phone Connect expecting to use it with my ATT 5840 cordless phone system with answering machine. I had the same experience as dankaz. I wouldn't call this working although VZW does. So back I went to the VZW store where a helpful (I thought) rep told me that the HPC would work with newer answering machines. So I spent $60 on a new Vtech cordless phone with answering machine. Nothing changed. Back to the VZW store where another rep called an internal support line where he was told that Panasonic systems would work if you adjusted the flash timer. So I bought a Panasonic cordless phone system with answering machine ($120). Nothing changed. I tried every setting of the flash timer to no avail. Then searching the internet turned up a device (Viking Electronics CPC-1 $75) which claimed to detect the busy signal and generate the CPC disconnect. Hooked it up and NOTHING CHANGED! I called the Viking Electronics support line and asked them how many busy signals were required before the CPC disconnect would be generated. The answer was 6! More money down the drain. So unless you have a perverse definition of "works with your existing answering machine" you probably do not want a Home Phone Connect.
Why do I want to use the answer machine? For call screening, which you can't do with voice mail.