It looks as though the current HCx models
might be the end of the line for the Garmin Etrex range, as there are previews of a new model range,
Dakota, which looks to have a lot in common with the Oregon but in a slightly smaller package.
http://www.gpsreview.net/garmin-dakota/Screen brightness and battery life are the two main areas where the Etrex C outperforms the Oregon, so if the Dakota does turn out to be a Etrex-replacement, it will be very interesting but hopefully the HCx will also be around for a good while yet.