Having two mobile solutions is a bother and mark has multiple times wished we do away with the old HAWHAW server.
I asked mark to look at the accesslogs of mobile.wikipedia.org and he counted 1.6M requests for transcode.php for todays log (22 hours). Much of this is probably explained by the fact that this mobile server scores pretty high on Google and en.m.wikipedia.org is unfindable on Google.
To deprecate ideally, we would need a full WML wap1 interface for en.m.wikipedia, or we should choose not to support that platform anymore (it's about 4 years old now, which is beyond the average lifespan of a phone actually).
When deprecated, we can redirect mobile.wikipedia.org to m.wikipedia.org