Not sure about the lifecycle, but you will find that Explorer has little to no documentation (at least the windows version), and even less tech support. Most of the tech support questions you may have will likely be that it 'out of our scope of support' . Listed as Included "Usage and concepts of documented software functionalities and workflows". However, since there is pretty much NO Usage documented anywhere, they can pretty much blanket say it isn't covered in support.
I have successfully been using it as I have same issue where Windows is required, and, touch screen support is required. Unfortunately, touch screen basically renders ArcReader useless or I'd still be using that as the GPS location not so much required in my case.
Can be difficult to maintain versions, as even though they aren't developing it, the installable version in windows seems to expire, so when I have to install on new computers, it will be a different version with different expire data. This becomes an issue as I have scripted the install/config so that I can run specific batch files to install/update. Well, need to completely re-build the batch file every time the app 'expires'.
Another huge issue for me is that multiple people may be using these particular windows computers at different times (shifts, for example). We have large basemaps and data downloaded locally so that the Explorer app will work when not connected to the internet. The way Explorer is designed, it is on a per user basis. So, if other user logs on/installs Explorer, it will make separate copies of each of the basemaps and data in each users folder. So, when you have a 20Gb background imagery loaded on the computer, it will copy that to each users folder that installs/opens the configured maps. So, 5 users are eating up 100Gb of hard drive storage to support one 20Gb basemap.
Although, not supported, you can do some mojo using mliknks in windows to keep from duplicating the large datasets (though, windows will still 'think' the mlinks are using up the storage, even though they are not).
In any case, like I said, I have been using it for a few years now on a select group of computers and is 'working' for the most part, but, if there were any other option at this time, I would most likely recommend it over Explorer.
R_
