you're doing a decent level of training then, in 40 mile weeks. Not surprised you comfortably got under 1hr 30.
Shows promise being able to do that off just a couple of months though.
Now, it's about how you get faster.
Some would have you doing reps and training based on your desired target pace, but I'd suggest training to your current pace zones.
What pace zones have you worked off in your "easy", and "steady", and how does your speedwork look?
I'd suggest a regular session such as 6miles at Marathon Pace.
Your other hard session would be track based stuff...again to your current zones...
For this to be effective you need to be spot on with your pace zone though, so I'll wait until you answer on your zones, and speed stuff.
Edited: 13/12/2012 at 18:51