Looking further at the election maps site...

Under the the Westminster boundary changes even more of SE23 will be moving from Jim Dowd's newly titled "Lewisham West & Penge" to Joan Ruddock's newly titled "Lewisham Deptford".

And the Honor Park area around One Tree Hill (west of the railway) is moving from "Dulwich & West Norwood" to "Camberwell & Peckham" - that doesn't sounds like an upgrade but it seems to make sense if you look at the map.

Other interesting info on each new seat...

Lewisham & Deptford: http://ukpollingreport.co.uk/guide/seat-...amdeptford
Lewisham West & Penge: http://ukpollingreport.co.uk/guide/seat-...standpenge
Dulwich & West Norwood: http://ukpollingreport.co.uk/guide/seat-...estnorwood
Camberwell & Peckham: http://ukpollingreport.co.uk/guide/seat-...andpeckham