A new table format supported by markdown is discussed in meta, as you might have become aware from links to this page
Inserting a table appears to be as simple as inserting e.g. the following:
| A header | Another header |
| -------- | -------------- |
| First | row |
| Second | row |
This does not render properly on Chemistry SE (or SO, I'm assuming not on other SEs either) of course. Chemistry SE uses MathJax to display tables.
Any comments on this feature? Is this markdown not available here (will it ever)?