If users have to pick a browser they will talk about it and some will like a browser and others will like other browsers and they will do this thing Microsoft hates called "compete". Eventually different browsers will develop different reputations based upon which ones best satisfy users and those are the browsers that will be the most popular.
How is this situation different than what exists right now without bundles? Firefox has achieved ~10% adoption rate at the expense of IE without any bundles (unless you want to count Linux distributions).
Bundling is an advantage as it equals guaranteed distribution but word of mouth doesn't require bundling.
Here's the problem with that. It requires constant vigilance and work on the part of the EU. Who tests IE's compliance? Will those people be bribed? Will they become lax after a few years allowing MS to go back to business as usual? How much time and effort needs to be put in to sustain this forever? It is fine in the short term, but does not solve the problem in the long term.
If all the EU is interested in is making a quick ruling and then patting themselves on the back for a job well done then they are wasting resources on pointless theatrics.
As far as I'm concerned if a government is going to step in and regulate then they better be ready to commit the resources to proper enforcement.
How difficult would it really be? If the Slashdot crowd hears about MS shenanigans then it's not exactly a big secret and one government official should be able to confirm or deny the reports. When it comes to bribery; not much can be done about that.
Once all the incompatible sites are universally broken then you've essentially restored balance and Microsoft would then have to convince web developers to ignore Firefox, Safari, the mobile browsers based on Webkit and Opera, etc.. to pick the proprietary Micrsoft technologies again.
I don't think it'll be an issue this time around since the market is a different place than it was in the 90s.
Then again, maybe I just don't understand the problem because based on that criteria it shouldn't be a problem right now...