We have something similar here (large multi-national), and I'd imagine it's standard enough in most larger companies, especially multi-nationals.
Changes under such a clause could work out in your favour, such as the implementation of flexible work arrangements (working from home, compressed week, etc.), or against you (longer working hours, restrictive dress code, etc.)
Generally nothing to get unduely concerned about. Have a word with an existing employee if you can, have the company in question ever exercised this clause, and if so, to what affect?
Leo