EGNOS is currently broadcasting from two (out of a planned three) satellites. You can view the current status (quasi real-time) here: EGNOS Real Time Performance
The status is 'Operational' but not currently certified for 'safety of life systems'. I do not know the precise set up of IFR approved GPS receivers, but I would expect (hope for) them to ignore these signals.
Non IFR approved sets may well be picking up and using the EGNOS signal. My Garmin GPS 96c aviation unit certainly does as do a number of different units we use in my business. On a Garmin unit you can tell if it is receiving the Differential signal by checking the 'Satellite Status' page. Signals with overlaid EGNOS/WAAS have a small 'D' displayed in the signal strength histogram.