Double patenting

Many years ago, I did a programme for Television Education Network in which I spoke about the House of Lords judgment in Asahi Kasei Kogyo KK’s Application. In fact the programme took the form of an interview, which was conducted by Jill Dando. Reading that complicated and lengthy judgment played an important part in making me more than just slightly interested in patent law.
The whole area of double patenting is more complicated than it first appears. There are several aspects to it: first, there's the fundamental question of whether an earlier application forms part of the state of the art, and second there's the specific issue of whether a second patent can be granted for the same invention. This can arise in divisional applications, but not exclusively so. It also raises the 'whole contents approach', explored in Asahi and rejected by Laddie J in Re Woolard's Patent. Double patenting also arises when a later European covers the same ground as an earlier national patent.
The reason I am turning my mind to such an arcane subject is a European Patent Office decision, T-1423/07, which confirms that there is no general prohibition on double patenting in the Convention. Previously, in an earlier decision T-307/03, it had invoked Article 60 to prevent double patenting, because it talks only about an inventor being entitled to the grant of a patent for the invention. That caused consternation at the time (see, for example, what the IPKat and EPLaw patent blog) but now the Board has decided that an application cannot be refused simply on grounds of double patenting. However, it distinguishes the 'parent and divisional' situation, where both have the same priority date, and the situation in the appeal, where the applicant had a legitimate interest in the second application which had its own filing date (later, of course, than the first).
All clear? No, I thought not. But interesting, certainly.