The answer to that, quite simply, is "yes". Overlapped is exactly what it is by design.
It was a difficult decision to make, so I attempted to address each audience. For the beginner, it has much of the older beginning level content as it was. The professional title is not really a replacement for the beginning title for someone that is a beginner for one simple reason: Completeness of discussion. While some of the actual prose is shared, you will find that the professional title is more targeted toward a "fill in the blanks" sort of model. It's meant to be a review instead of a introduction. All the "beginning" topics are, by and large, still there primarily for reference, however, things move along faster and entire areas of discussion are downright skipped. Likewise, the intermediate to advanced user can't really just get by on the beginning title as the depth that more advanced topics are addressed is considerably different. Some topics that are in the pro title are not in the beginning title at all. Even in the shared topics, you might find things like internal index layout being discussed in the pro title, but not in the beginning title.
The short rendition is that there is perhaps as much as 30% overlap between the titles, but, at the same time, they are seeking a different depth and each contains discussion that the other does not have. They are most definitely not the same book. If you're an intermediate to advanced SQL Server person, you would want to go straight to the pro title. The "new to SQL Server" person will want the depth of introduction found only in the beginning title, and that book should serve them will for the vast majority of their needs for the first 6 months to a year of working with SQL Server.
I hope that addresses the issue for you!