Yes, Harvey's article is very interesting. It makes a lot of sense that individuals who belive that worry is a good idea in some way (i.e. "I'll be prepared," "I won't be taken by surprise," "I'll get to the root of the problem," etc.) will put more time and energy into worrying and will persist with it even if it interfers with sleep.

These beliefs and thoughts about one's own cognitions play an important role in many problems. Adrian Wells discusses their role in GAD and PTSD in an excellent chapter in Contemporary Cognitive Therapy: Theory, Research, and Practice (Guilford, 2004) and has an article coming out in Cognitive and Behavioral Practice that I am looking forward to. By the way, you can impress your friends and relatives by referring to these cognitions about cognition as "metacognitions."

It certainly makes sense to address these metacognitions as part of treating insomnia and I find that it is often quite useful. I'm not sure I'd go as far as predicting that this intervention will be more effective than other interventions because there are many cognitive and behavioral factors that play a role in insomnia and I haven't seen any studies comparing the effectiveness of different interventions.

Other dysfunctional cognitions and behaviors commonly observed in insomniacs include:

a belief that insomnia will have catastrophic consequences,

a tendency to avoid dealing with worries and concerns during the day so that they remain unresolved at bedtime,

a tendency to "try hard" to get to sleep and to quickly become frustrated when they have difficulty falling asleep,

anticipatory anxiety as bedtime approaches,

and dysfunctional strategies for coping with insomnia such as napping which disrupts the sleep cycle or the use of alcohol to make it easier to get to sleep (which suppresses REM sleep)

After a good assessment, there usually are quite a few cognitions and behaviors that are useful to address.