So all this information is subject to someone correcting me, and is just barely a step above hearsay, but here's what I understand, and my interpretation, so take this all with a nice large grain of salt.
Currently the SmartZone system is actually backed by a P25 core. The conversion happened a while ago. The connection to the individual sites is via SmartX. Sounds like most of the SmartZone systems in the U.S. still kicking around that aren't actively being converted to P25 with a great deal of pace are operating this way. Gets critical traffic management components off of ancient computer hardware/software, although you are still stuck with a lot of the older technology used for SmartZone like non-ethernet (T1/Analog) site connectivity.
Last I heard from folks there was they were being told the conversion to P25 for the statewide public safety system would happen in about 2-3 years from now (this was almost a year ago and they were told 3-4 years).
I do not know enough about state politics in Delaware, but basically it seems like the P25 DELWIN system was designed explicitly for state agencies to supplement, rather than supplant the SmartZone system. Articles from the 2009 timeframe when it was announced indicated the intention of the project was to "piggyback" rather than replace the SmartZone system. There could be more at play here - example, some state agency (or group of agencies) wanted to usurp control of statewide communications from the Division of Communications by giving it a fancy name and waving around the use of (at the time) new more interoperable technologies. You see this happening all the time, and while it sort of has a negative connotation to it, it isn't always. Example is the
COIRS system in Ohio. I guess the point is, there Division of Communications may be lacking authority to manage something, or answer to someone different than the folks who put the DELWIN system up.
You will note that the
Division of Communications page on the 800MHz system makes ZERO reference to DELWIN. Normally I would chalk that up to an outdated website, but DELWIN was announced in 2009, and that page references 2014 activities in the past tense. Further, there and in other places they reference coverage enhancements, use of BDAs/DVRS, etc. So in my mind DELWIN was an answer to bad coverage for State Corrections, with a longer endgame of linking to whatever happens with the 800MHz system (even though the pieces are in place for Motorola to basically flip a switch and kick on P25 to start deploying site equipment, doesn't mean they could decide to put a P25 system out for bid). Whatever state agency manages that would be able to keep deploying to large state campuses but gain interoperability with the state - capacity would remain their issue, not the states and so corrections activities that rarely leave the campus remain on campus, but when they do off campus activity, they would be able to be interoperable with state police and others.