Scored 945. I think I missed about 3 questions from 55.
It took 4 weeks to prepare (after work and on weekends), ~160hr total.
Recipe:
1. Get training if you can. I watched Trainsignal videos.
2. Read. I chosen MSPress book. Way outdated, doesn't cover R2 changes and Sharepoint 2010 Foundation and chapters about Terminal Services may confuse, because Microsoft changed TS to RDS and whole bunch of terms changed along.
To learn R2 changes I started at Technet:
What's New: Changes in Functionality from Windows Server 2008 to Windows Server 2008 R2 and explored unfamiliar features by browsing deeper trough Technet. For example knowing about managed service accounts became very handy during the exam.
Sharepoint 2010 Foundation - for start there is a pretty good online source
Microsoft SharePoint Foundation 2010 - Download, Articles | TechNet
4. Lab, lab and once more - lab. Most important part. Spent about 2/3 of time labing - practice is really crucial for this exam. Book doesn't have enought practice scenarios, so I had to made bunch of them up myself, end up having over ten virtual machines, with Clusters, IIS, RDS and Sharepoint farms. Probably pushed every button there is

As for Hyper-V learning - this is why I always recommend use Hyper-V for all labing (of course only if you are going for MS Certs). If you had used Hyper-V from start, by 70-643 exam you will already have mastered required skills - it saves time dramaticaly.
I also use WDS for installing new virtual machines - saved time once again.
5. Preplogic Megaguide for Craming before exam day. Good for review, especially if you bought only for 1$.
Overall exam one of toughest i have taken. Possibility to pass it without labing very doubtful.
I'm feeling like a squeezed lemon, but don't have time to rest - 70-647 is only three weeks away and failure is not an option