installing GWT or anything else results in "XYZ not available - see error log"

And error log says:

eclipse.buildId=unknown
java.version=1.6.0_31
java.vendor=Apple Inc.
BootLoader constants: OS=macosx, ARCH=x86, WS=cocoa, NL=en_US
Framework arguments: -product com.jboss.jbds.product.product -keyring /Users/max/.eclipse_keyring -showlocation
Command-line arguments: -os macosx -ws cocoa -arch x86 -product com.jboss.jbds.product.product -keyring /Users/max/.eclipse_keyring -consoleLog -showlocation

Error
Thu Jun 21 23:03:32 CEST 2012
Unable to connect to repository http://devstudio.jboss.com/5.0.0/5.0.0.GA.target-platform/compositeContent.xml

java.net.ConnectException: Operation timed out
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:432)
at java.net.Socket.connect(Socket.java:529)
at sun.reflect.GeneratedMethodAccessor85.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.commons.httpclient.protocol.ReflectionSocketFactory.createSocket(ReflectionSocketFactory.java:140)
at org.apache.commons.httpclient.protocol.DefaultProtocolSocketFactory.createSocket(DefaultProtocolSocketFactory.java:125)
at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)
at org.apache.commons.httpclient.MultiThreadedHttpConnectionManager$HttpConnectionAdapter.open(MultiThreadedHttpConnectionManager.java:1361)
at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:387)
at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:346)
at org.eclipse.ecf.provider.filetransfer.httpclient.HttpClientFileSystemBrowser.runRequest(HttpClientFileSystemBrowser.java:227)
at org.eclipse.ecf.provider.filetransfer.browse.AbstractFileSystemBrowser$DirectoryJob.run(AbstractFileSystemBrowser.java:69)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)