No Hogwarts Express at the end of HBP?

[Catlady (Rita Prince Winston)]

No: HPFGUIDX 143565

Kelleyaynn wrote in
http://groups.yahoo.com/group/HPforGrownups/message/143487 :

<< Can anyone think of any significance for the book not ending with
the trip home on the Hogwarts Express? I believe every other HP book
ended at King's Cross. It makes me wonder if the seventh book will
pick up essentially where HBP left off - if maybe there is more that
will happen on this day, or before Harry gets back to Privet Drive that we
don't know about yet. >>

I can think of two possible reasons. One is to symbolise that Harry is
no longer a schoolboy, but now a hero on a quest, who will not be a
Hogwarts student in the next book. The other is that JKR has said that
Book 6 and Book 7 are more like two halves of one book (sorry, I can't
find the citation), in which case the ending of HBP is not the ending
of 'the book'.