This looks like a cop-out, but here is how you do it:
[wave id=”!w+9wEkpHp-B” bgcolor=”#000000” font=”Verdana, Arial, Helvetica, sans-serif” font_size=”11” width=”500” height=”700”]

Oh, and you need the Wavr plugin.

P.S. If you don’t see anything, you probably don’t have a Google Wave account. Which would make embedding a wave in your blog… ehm… difficult.