Announced at PDC this week
http://www.microsoft.com/downloads/details.aspx?FamilyID=6806e466-dd25-482b-a9b3-3f93d2599699&displaylang=en
Finally a version of blend that will open vs2010 projects (and of course handle Wpf4 and Silverlight 4)
It will run side by side with Blend 3
Enjoy 
It's true what they say, to learn new technologies it's simple a matter of ABC (Always be coding), I've watched many the video, read many the book but it's only when I went to try to do something the it sinks in.
Like tonight while trying to host a WCF service on my Windows 7 machine I came across a problem that you'd only find by ABC.
HTTP Error 404.3 - Not Found
The page you are requesting cannot be served because of the extension configuration. If the page is a script, add a handler. If the file should be downloaded, add a MIME map.
The solution.
Control Panel/Programs and Features/Add or Remove components/Microsoft .NET Framework 3.5.1 section.
I checked the two Windows Communication Foundation checkboxes shown below (the second box enables Windows Activation Service - WAS so that IIS can host WCF services that can be called using non-HTTP bindings such as TCP) (nice!)
http://errorlist.codeplex.com/
ErrorList
I recently wrote a control that tries to replicate the error list seen in Visual studio.
The control is dependant on .NET 3.5 SP1. because it uses the WPFToolkit.
I'm hosting a sample here. [Update August 2012 My host has stopped xbap application types, sorry]
Screenshot
I've had a few people asking me how did I host Silverlight 3 in blog engine.
Silverlight Usercontrol
It was pretty simple really (when you know how)
Basically Silverlight3 needs an <object> tag.
So I created a user control with the object tag and some script handling for client side errors (actually VS2010 did all the hard lifting).
<%@ Control Language="C#" ClassName="SilverlightControl" %>
<script runat="server">
</script>
<script type="text/javascript" src="~/Silverlight.js"></script>
<script type="text/javascript">
function onSilverlightError(sender, args) {
var appSource = "";
if (sender != null && sender != 0) {
appSource = sender.getHost().Source;
}
var errorType = args.ErrorType;
var iErrorCode = args.ErrorCode;
if (errorType == "ImageError" || errorType == "MediaError") {
return;
}
var errMsg = "Unhandled Error in Silverlight Application " + appSource + "\n";
errMsg += "Code: " + iErrorCode + " \n";
errMsg += "Category: " + errorType + " \n";
errMsg += "Message: " + args.ErrorMessage + " \n";
if (errorType == "ParserError") {
errMsg += "File: " + args.xamlFile + " \n";
errMsg += "Line: " + args.lineNumber + " \n";
errMsg += "Position: " + args.charPosition + " \n";
}
else if (errorType == "RuntimeError") {
if (args.lineNumber != 0) {
errMsg += "Line: " + args.lineNumber + " \n";
errMsg += "Position: " + args.charPosition + " \n";
}
errMsg += "MethodName: " + args.methodName + " \n";
}
throw new Error(errMsg);
}
</script>
<div id="silverlightControlHost">
<object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%">
<param name="source" value=""http://www.briankeating.net/clientbin/blogengine.ui.xap"/"><%Silverlight.xbap%>"/> // where <%Silverlight.xbap%> is location of silverlight xbap
<param name="onError" value="onSilverlightError" />
<param name="background" value="white" />
<param name="minRuntimeVersion" value="3.0.40818.0" />
<param name="autoUpgrade" value="true" />
<a href=""http://go.microsoft.com/fwlink/?LinkID=149156&v=3.0.40818.0">http://go.microsoft.com/fwlink/?LinkID=149156&v=3.0.40818.0" style="text-decoration:none">
<img src=""http://go.microsoft.com/fwlink/?LinkId=161376">http://go.microsoft.com/fwlink/?LinkId=161376" alt="Get Microsoft Silverlight" style="border-style:none"/>
</a>
</object><iframe id="_sl_historyFrame" style="visibility:hidden;height:0px;width:0px;border:0px"></iframe></div>
One approach for validating child controls on windows froms is to
Validation.
- Add a Validated event handler to all child controls you're interested in.
- On a button event handler call this.ValidateChildren();
This will ensure the validation routine on all child controls will be called, if for example you've added an ErrorProvider control extender to your form you can set it up in the validated event handlers.