mover625. Looking at the FCOM, there are a lot of systems that will go INOP when DC Bus 2 fails, but they also note that failure could happen on a sub bus, which obviously would take out less.
As a list of equipment (not complete) dependent on Bus 2 (which includes all the ACARS warnings):
INOP SYS
SPLR 1+2+5, ELAC 2(1), SEC 2+3
VHF 2, CTR TK PUMP 2, LGCIU 2
REVERSER 2, CAB
PR 2,
FAC 2, L TK PUMP 2, R TK PUMP 2
ENG 1 LOOP B, ENG 2 LOOP A, PACK 2 REGUL
FCDC 2, MAIN GALLEY, Y ELEC PUMP (if selected ON)
BRAKES SYS 2, F/O STAT, R WSLHD HEAT
R WNDW HEAT, AP 2, FCU 2
LGCIU 1 (2)
Other INOP SYS
SFCC 2, R cabin fan, F/O wiper
F/O rain rplnt, Eng 1 and 2 fire ext btl 2, Autobrake (due to loss of 2 SECs)
BMC 2 Bleed, X feed auto control, RMP 2
FQI channel 2 zone controller, sec channel SDCU 2
Brake fan, Eng 2 oil low press and qty ind, R loudspeaker
rudder trim ind, FMGC 2 CDLS