Update: Sound and fury
I expected to get a few corrections when I posted this, and I have. Let me shine the bright light on a few factual errors in the original post.
First, I was flat wrong: Oracle 10g Express isn't an Oracle Lite derivative. Express is a limited version of Oracle's 10g product line. The Express version pulls out certain features, including support for spatial data, grid deployment, some enterprise management tools, and others. More significantly, deployment is limited to single-CPU systems managing no more than 4GB of data. Total cache size is limited to 1GB.
I guessed early, and I think my guess was pretty clever. Too bad that's not enough!
Second, I said that 10g was a preannouncement, not available. Not quite right. A beta version is available for download, but the production version won't be ready until later this year. I've not downloaded and test-driven the product myself, but I understand that there were a few glitches in the beta installation that were relatively easy to work around, and that the binary then installed and worked as advertised.
Finally, Rex Wang commented on my original post that Oracle's move was the same as an earlier announcement by Sybase. He was right, and I ought to have pointed the same thing out. In fact, if any company should look on this move with concern, Sybase should. If there are two no-charge, low-end databases available from big relational companies, you'll probably take the one Oracle offers.
My original conclusion stands: It's community, not price, that will determine the success of these products in the market. I believe that the open source players are much more successful there already, and I am deeply skeptical that free beer builds lasting relationships.