Charts in Google Spreadsheet are imminent
It wouldn't surprise me if a significant upgrade (that includes charts) is rolled out very soon. You can find references to this coming feature in many of the externally linked files in the source code:
Here is a list of chart types that will be the supported according to the "charts_messages_en" file:
_C[12] = ('Pie');
_C[13] = ('Columns');
_C[14] = ('Bars');
_C[15] = ('Lines');_C[25] = ('Scatter');
More interesting pieces of code suggest that charts will be displayed as "vml" for Internet Explorer and "svg" for other browsers that support it (like Firefox and Opera):
var c=xm(),d=xd[V].indexOf("MSIE")>=0?"vml":"svg";
...
var e=this.Ib("svg");
e.setAttribute("id","chart");
e.setAttribute("width",a);
e.setAttribute("height",b);
this.F.getElementById("chartArea").appendChild(e);
Until now, the only reference to charts in the source code was an image named "testChart.png" that didn't even actually exist. I would say this is enough evidence to "get our hopes up".