Here is a more detailed map of Phase 1 from
the press release from UT today:
You can clearly see that the park largely survives.
The release also confirms that the Frank Erwin Center will be torn down and replaced, but not for at least 6 years. There are some rumors on Orangebloods.com that it could be relocated to Mueller. I don't know how likely that is. I'm not sure I like that idea. I'd rather it be an on-campus arena, although a Mueller arena would certainly enliven that area of Austin in a huge way.
Here's a map from
this KUT News article of what the complete buildout could look like, with the Erwin Center completely demolished and replaced:
Man, this will radically change Austin as we know it. That part of town will be completely unrecognizable.