That's not really (not only) UTF-8, but an encoding seen, for example, in the subject line of Mime messages having non-Ascii characters in them.
See http://en.wikipedia.org/wiki/MIME#Encoded-Word for more details.

In short, not only it is UTF-8, but it is also Base64 encoded, to avoiding having 8bit chars in the message.

To my knowledge, there is no Base64 encoding-decoding class in base Java, so you have to locate one to do the job.

OK, I am glad to learn that I was wrong...

1. String s1 = "=?UTF-8?B?Tm93IFRocm91Z2ggUHJlc2lkZW50c+KAmSBEYXk6IEVHR1hlY3V0?=";
2. String s2 = "=?UTF-8?B?aXZlIFNhdmluZ3Mgb24gQ29tcG9uZW50cywgRWxlY3Ryb25pY3MgJiBNb3Jl?=";
3. String s3 = "=?UTF-8?B?IQ==?=";
4. 
   
5. void setup()
6. {
7.   println(decode(s1));
8.   println(decode(s2));
9.   println(decode(s3));
10.   exit();
11. }
12. 
    
13. String decode(String s)
14. {
15.   String eu = s.substring(10);
16.   byte[] ba = javax.xml.bind.DatatypeConverter.parseBase64Binary(eu);
17.   try
18.   {
19.     return new String(ba, "UTF-8");
20.   }
21.   catch (UnsupportedEncodingException e)
22.   {
23.     println(e);
24.   }
25.   return null; // Only if we had the exception, which shouldn't happen if you don't change the encoding...
26. }

Thank you for the feedback.  The item in question is a subject line from vendors such as TigerDirect, NewEgg, and others.

It turns out that Windows Live Mail does decode this correctly, but my old version of Eudora5 does not.

Your assistance is appreciated.

No problem, I learned a couple of things while answering...