Both Adobe and Microsoft are moving to a pattern of constant updates.
The new ‘improvements’ to Windows 8 (codenamed Windows Blue) will the the first edition that will undergo constant modifications.
Adobe will be moving away from it’s ‘Creative Suite’ and concentrating on offering it’s apps (for rent) in the cloud.
For schools then this means that every time you start up the software you could expect some small change so the step by step guide might have a shorter lifespan than normal.
The other issue (of course) is cost. Whilst many might actually prefer a rental model as the costs are more consistent (I believe most schools use the ESS agreement for example) it does mean that you can no longer delay upgrading a while longer to save money.