Keep it if you have the space. It's paid for, and you never know when it'll come in handy.
You could plug a Drum Machine into it, or a kids keyboard with a rhythm feature for practising along with. Maybe even experiment running two amps with a stereo pedal.
Then again, if the $100 to $150 you can fetch for it would buy you that nice pedal you've been eyeballing...
Gearlist:
Electric: Ibanez 'AS103', Fender Dlx Nash Pwr Tele, Fender Squier '62 JV Strat, Squier '51, Squier 60's Classic Vibe Strat, Epi Elite LP Studio, Hagstrom Swede Acoustic: Larrivee LV-03RE, A&L AMI, Yamaha FG340-T Bass: Yamaha BB 450 Amps: Roland JC-120, JC-50, Peavey Classic 30, Fender Super Champ XD Pedals: Marshall Guv'nor Plus, Danelectro Cool Cat Drive, Transparent Overdrive, Digitech Digiverb, Bad Monkey, Ibanez TS-9, Boss AC-2, CE-5, CS-2, DD-3, DF-2, DS-1, FV-100, GE-7, OC-2, PSM-5, SD-1, TU-2, DVM~BYOC 'Lush Puppy' Chorus