You mentioned in passing that you have a feeling that Picasa isn't surviving for long due to it's "old-fashionedness".
Considering how important "usefulness" and "usability" are by now, maybe add a criteria along those lines - how large is the "your mom uses it and likes it" factor, how "contemporary" are the UIs, how much effort puts Google into polishing it (it does a lot with G+ and Gmail for example) - something like this.
Another criteria could be "level of integration" - how much can you use a Google product as a standalone project or how deeply connected is a product into another one (e.g. Picasa used outside of G+) - which might in the end indicate not a direct shutdown but a product's dissolution into another one.
Considering how important "usefulness" and "usability" are by now, maybe add a criteria along those lines - how large is the "your mom uses it and likes it" factor, how "contemporary" are the UIs, how much effort puts Google into polishing it (it does a lot with G+ and Gmail for example) - something like this.
Another criteria could be "level of integration" - how much can you use a Google product as a standalone project or how deeply connected is a product into another one (e.g. Picasa used outside of G+) - which might in the end indicate not a direct shutdown but a product's dissolution into another one.