I suppose if you didn't keep up with current best practice, when Sept 2008 comes around you would be breaking the law! The previous Birth to 3 Matters (for 0-3) and Foundation Stage (3-5) were guidance only, but the Early Years Foundation Stage (EYFS) is law.
On the subject of Child Protection, can you imagine if, as a worker in early years, you didn't know about Every Child Matters? No knowledge about why it has been implemented or what it entails? You would be graded unsatisfactory by ofsted as you would be failing to keep children safe.
Same with the new Safeguarding children board we have to mention in our Safeguarding policy (that used to be Child Protection)... keeping up-to-date with things like this help us to be professional and to do our jobs properly... it's not optional, it's vital!
Hope this helps