I'm confused. Is the information on the Marketo exam preparation webpage accurate? If the practices tests are not recommended, then why does the webpage still link to them? Is the 3-hour prep course ready? Why is this information not on the exam preparation webpage?
Will there be a practice test soon? Taking away a free resource to replace with another $375 class is not that Kosher nor helpful as practice tests are some of the best way to prepare.
The new MCE exam and specializations are out now along with the training sessions. Details are here: Marketo Certified Expert and you can register for the three hour prep courses here: Training Catalog. There will no longer be a practice exam, and I have heard that the new exam is quite different and more difficult.
I'm not sure where the more difficult came from but I would say it may be a bit different in areas. Previous exams tended to contain a bit of "what's on this menu" or "where do you go to...". The new exam is more concept in nature. "If you wanted to do xyz, how would you accomplish this?" type of thing.
I would still prep but I think if you have a base level of the concepts behind what Marketo does (engagements campaigns, segmentation, different types of programs, reporting, etc.), it should be fine.
If anything, it may be easier because you do not need to know what's on a menu in an area you never or rarely use.