Sony employee James Gallagher confirmed that you will be able to watch the SCEA press conference in PlayStation Home:

You will be able to watch the SCEA press conference in Home, in a new space called the Presentation Podium. We’re still waiting for confirmation of when.
I know quite a few of you have been asking this question, so apologies for not replying to every one – busy times!

Now, I hope this is going to be more than a simple video feed like the laggy game trailers in the Home movie theater. I hope there is a proper explorable booth, a stage space, live Sony avatars, separate game trailer screens, and a full Home experience beyond what we can already get through web coverage. Great news!