A few interesting data points from the "
Date Based Ticket FAQ" thread on the TPAS (see post #5):
These new tickets are not MYW tickets. They will be referred to as Walt Disney Theme Park tickets. How this will affect any upgrading of MYW tickets to additional days or APs is yet to be determined. When MYW tickets were introduced, previous tickets were still honored for whatever entitlements they held but could no longer be upgraded.
Tickets purchased as a part of a package will be valid for the length of stay even if they would have expired earlier under the new ticket rules. IOW, a 5-day pass which is supposed to be good over 8 consecutive days would be valid until the end of your 14-night stay if you book a package of that length. This does not apply to all parts of split stays.
However, tickets not purchased as a part of a package will still expire on the expected date (5-day tickets expire 8 days after first use). This applies even if the guest is staying onsite.
No word on how this might affect DVC owners, who do not purchase packages but may want to stretch a ticket out over more days. DCL will be selling special 14-day expiration tickets to cruisers who bookend resort stays around their sailing but the tickets need to be purchased by calling DCL. It would be nice if DVC would do something similar for members but I'm not counting on it.