Been doing this for 9 years or so. Its not hard to maintain your gains per se, but progressing might be harder for you. If you aren't going to be doing this for very long, don't worry too much. If you are use to always training the same way on the same days, be prepared to drop that mentality. I still never feel the same way on off days, so I try to get the most out of my workouts. If I feel great, then I do everything I want. If I feel like crap I don't try to force myself to do much, as you are already in a sleep deprived state sometimes. Overtraining is much easier with this type of schedule.
My work area changes every set, so what has worked for me is to usually plan heavier workouts on my off days. If I can/have time to work out before working nights, it will always be less taxing workout.
Sleep is the biggest issue for me. For the first few years I could easily adjust to the lack of sleep, but it eventually catchs up to you. If you live with anyone, let them know how the night shift will effect everything (ie, let them know you need to sleep and if they wake you up during this time you will kill them. 'nough said).
My worst sleep problem is actually falling asleep before going back to work on days. The night before is a killer. I used to never sleep well for this, and it starts a work set off on a bad note and I felt "off" on the set I should feel best on. Some supps that can help: Valerian, melatonin, 5-htp, and the relatively new REM-3 from usplabs. I'm still testing the latter, but for the day set, this stuff has really helped with me feeling more awake all day.
I don't know what kind of schedule you'll have (3 on 3 off, eowo, etc etc.). Even if I did, I couldn't say what will definitely work, so the bottom line is you have to be flexible and see what works best for you. Have some quidelines that you are determined to stick to (ie, X number of hours of sleep/rest, calories etc). Its way to easy to try to do too much when you work nights. Figuring out how best to stick to your guidelines will take some time, but I can assure you ignoring the sleep issues on this kinda schedule will eventually kick your ass in multiple ways. It can affect so many aspects of your life, losing some gains is minor to what else gets affected.
perhaps if you post the type of rotating schedule you'll have and the shift length etc. we can give more suggestions.
TSC