I absolutely LOVE Ginny! And I thought that JKR did really well at portraying Harry as, first and foremost, a teenager. I just kept saying, "Harry is such a brat!" I too was a little confused as to why he didn't see the thestrals to begin with.
I'm all for Harry and Ginny getting together. Most of my fellow HP addicts here think that JKR will kill Harry at the end -

I don't agree.
I thought Tonks was the greatest! I love how JKR captured everything about adolesent reactions with the whole Harry-Cho thing. Hermione cracked me up when she was telling Harry how he should have asked Cho to go with him to meet her.
The 6th book better come out quicker than this one or I'm tracking down JKR and standing over her should with a gun until she finishes it.