说话者实际要表示对“他”的身份的惊讶吗？

1）wonder as verb is explained as follows:
to think about something that you are not sure about and try to guess what is true, what will happen etc

2）I wonder who she is. 我想知道她是谁。
此处wonder为“想知道，对---有疑虑”，一般后跟who/what/how等从句。

3）当 wonder 表示 “ 感到惊异 / 惊讶 ” ， “ 感到疑惑 ” ，常见的用法如下：
（ 1 ）与 at 连用。
e.g. I wonder at your allowing her to do such a thing. 我对你允许她做那件事感到惊讶。
I don't wonder at his words. 　我对他所说的话并不感到惊讶。
（ 2 ）后接 about 短语，表示 “ 对 …… 感到疑惑 ” 。
e.g. I wonder about my future. 我对我的未来感到困惑。
I was wondering about that. 我对那事感到新奇。

综上，I wonder who he is.无“惊讶”之意，只有“想知道或对 …… 感到怀疑”含义。
说话者实际要表示对“他”的身份的“怀疑”或“求知欲”。