FYI, I just noticed this announcement (from a couple of months ago) about the end of NPAPI support in Chrome + Firefox, which will mean the end of native browser plugin support:
http://blog.chromium.org/2013/09/saying-goodbye-to-our-old-friend-npapi.html
This doesn't come as a big surprise, as they've clearly been keen to ditch it for a long time, but it does seem to be officially moribund now.