I'll cut straight to the point - I think Battlegrounds are a home run! While not perfect, I do think Battlegrounds are very fun, and if they get tweaked and expanded going forward, this game should have long legs. As a level 59 druid with only 1/2 a set of my rare class gear, I still am able to kick some ass out there. Both the CTF battlegrounds and the Alterac Valley Battlegrounds have been fun. I haven't even done a guild group yet other than running with Tav (or following Tav around while he capped flags is more like it). It will be much more fun running in an organized group.
Which brings me to point # 2 - Super, come back now. This is worth your time. We can have a lot of fun with this if we have a decently skilled guild zerg that can follow instructions.
I made no secret I was down on WoW before battlegrounds came out (but yet continued to play, go figure). I think solo grinding to 60 on a post-honor patch PVP server before battlegrounds came out was much more painful than levelling my first char over on Azgalor. Especially if you take it personally when you die like I do!

But that's cool, 1/2 level more and I can be full time PVP again! WoW now has legitimate PVP rather than the joke pvp zerging around Kargath & Tarren Mill that people were trying to call PVP before. CTF has been a lot of fun. (Before my 3 years of DAOC, I played Unreal Tournament CTF hardcore, and I love CTF.) Once people figure out all the strategic points on the map so it's not just everyone running around, it's going to be great. Alterac Valley zerg map is fun too. The battlefront remains fluid up and down the valley. The uneven terrain and bottlenecks before strategic points make it more interesting. I again think it was a decent level design.
On the downside, the wait time to get in is lame. They need more instances! Yesterday afternoon I was able to play a bunch of CTF without waits in between, but at night during prime time it was a 37 minute wait to get in. That's ridiculous. Worse than waiting for Drutt to get his shit together and head out. (DAOC Merlinites may understand that reference). I also think CTF needs more than one map. I'm not sick of this one yet, it's a good level design, but variety would be good.
I'd also like to see Battlegrounds have more of a lasting impact on the overall game. DAOC relic runs were cool not just because of bragging rights, but you also were doing something that provided lasting benefit to the whole realm. Both offense and defense of relics actually mattered, not just that night, but until your enemy managed to do the same. Same thing with taking enemy keeps to open the Darkness Falls dungeon. It mattered, it helped your realm and hurt your enemies. I liked the realm call to arms. So I'd like to see the zerg battlegrounds become more, with some really hard central objective that both sides wanted to accomplish and wanted to prevent the enemy from accomplishing.
You know what would be awesome with the CTF map? If they made it so that if you could win 3-0 vs your opponent, you could stay in the instance versus a new set of opponents, except now they outnumbered you! Round 2 would be 10v15, round 3 would be 10v20. If a group can advance and win 10v20, then give them some sort of special reward.
The most fun for me in DAOC was when 2-3 groups of BWC would defeat a huge zerg. I like being outnumbered and winning.
Well thats all, I've wasted enough time at work. See you all out there