The excellent "Plymothian Transit" blog has more details. All changes have a start date of 14th April.
http://www.plymothiantransit.com/
7/7A: new routes between Exeter and Totnes (7) or Torquay (7A) replacing 46 and part of X64.
12/N12: introduction of Summer timetable. Late night journeys introduced on Friday night/Saturday morning and Saturday night/Sunday morning.
22: new timetable with later journey to and from Dawlish Warren daily.
23: new timetable with off-peak and Saturday service rerouted via White Rock Way (new housing on outskirts of Paignton)
31: revised times on Saturday mornings and Sundays.
32 (Torquay): (not mentioned but presumably will be replaced by new 35A/35C)
32 (St Budeaux): revised route and timetable.
32C: incorporated into 35A/35C registration - no change to route or timetable.
34: withdrawn, replaced by 35A/35C
35A/35C: new circular routes replacing 32 and 34.
46: withdrawn, replaced by new route 7A
X64: withdrawn, replaced by new route 7 between Exeter and Totnes and by new route 92 between Totnes and Dartmouth.
77: new Newton Abbot town service between Hele Park and Buckland. Every 30 minutes Monday-Saturday, hourly Sunday.
88/88A/88B: withdrawn between Newton Abbot (Town Centre, Sherborne Road) and Buckland, new route 77 provides an alternative service.
92: new route between Totnes and Dartmouth replacing part of X46 and operating to revised times.
110 (school route): afternoon journey retimed.
Fox: minor timetable changes to morning journeys.
Gold: new timetable, incorporating additional Monday-Saturday evening journeys and an extra journey in each direction on Sundays.
There is no mention of the Torbay open top 122 service but I would expect it to commence from the same date.