So I just took and passed the test and I must say I was not completely impressed with the level of difficulty, of course I may have barely passed!
Is there a plan to have an Engineer or Expert version which goes into much more detail about custom pollers, DB structure, application mechanics, etc..?
Congratulations on passing! Sounds like your level of knowledge and hands on experience are above the requirements of the exam.
We are discussing what comes next for SolarWinds certification, but nothing has been decided yet. Being only 2 weeks past launch of this exam, it will be a bit before next steps are decided.