I think schools are always going to be 'behind the times' to a certain extent, when compared to the technology that people buy into their homes. For one, the amount of testing needed before new technologies can be uesd in the classroom slow the process down. I've heard, plenty of times, from students in my schools saying " our computer at home is far better than these ones at school" or " why can't we have X because we have it at home". Having said that, with competent ICT staff and a good solid structure in place for replacements and progression then schools should never be too far behind.
The part about teachers struggling to keep upto date with the technologies is something, in my opinion, that can be combated by how the change in technology is done. When new systems are put in place, be it new versions of office or new versions of Windows, they should be done correctly. Allowing for training, allowing for schemes of work to be changes and allowing for staff to get their head around the new technology before it's pushed out for use in lessons.