Are your announcements and every other element of the service about what God has done for us? Probably not.
Announcements no, but most everything else, yes.
Why would what you sing about be held to a "higher" standard of what is acceptable? The scripture does teach us to honor our leaders and to be good citizens. Personally, I believe it is overly legalistic to dictate that every song must meet some sort of litmus test of what is considered "worshipful." That being said, I'm sure there are examples of songs that I would feel are completely inappropriate, I just don't think the hymns about our country fall within that category. However, I consider that a "do you eat meat" type of question and don't hold a hard-line/either-or view on the subject.
I'm not trying to judge anyone on this by any means. What I'm looking at is that we have a worship service where we get together as Christians and worship God. Why do we have songs in our service? It's for worship, or more specifically an expression of our worship. You said we are to honor our leaders. I agree. But to me, when I replace my usual songs about God and replace them about my country, I'm wondering if this is pleasing to God. I believe Winman mentioned something about thanking God for our country. I know the song our choir will sing this Sunday is about that.
I guess I'm more referring to the more secular songs that are patriotic. The Song, "My Country, 'Tis of Thee" is a song about America. It does mention God in the 4th verse, but the other part of the song doesn't.
What got me thinking about all this was where I heard someone almost equate spirituality to patriotism. Now, I love our country and am thankful to God that I live here in the US where I'm free to worship Him!
Anyway, not here to judge anyone about it. My church will be singing them this Sunday. It's just something I've been thinking about lately. We go to church to worship God, and my desire is to make that the object of our worship in Church.