Well, my FH and I agreed we could kiss once engaged and so far I'm very glad of this!!! Getting naked/having sex on the wedding night is scary enough and I'm very glad my FH will at least know how to give me a really lovely, passionate kiss.
I also think it's important to draw a line between what is "right" and what is "wise." The scriptures are CLEAR that premarital sex is wrong (and arguably other things--petting/nakedness). However there are many cultures where one kisses even strangers on the lips!!! So I think every couple needs to examine what is WISE for them and won't LEAD them to do things that ARE clearly wrong. So, while I definitely think waiting might be wise for some people (and respect a couple's decision either way!), I've also seen already-"awkward" couples just make things more awkward...
and for some (women particularly) it can reinforce strange ideas they have about their sexuality. Even for me, while I feel like I'm above-averagly comfortable with my sexuality, in my community growing up we heard a lot of "no-no-no!" and it can be hard to transition to thinking pleasure is beautiful and acceptable in marriage. Kissing is fun. Holding hands is fun. That doesn't make it wrong. It's beautiful.
For my FH and I, kissing has been a lovely way to symbolize our growing romance as we have committed and await the wedding day. (Though, I would note, we have a short engagement--I don't think it would have been wise for us
to begin kissing if our engagement was long!) We discussed VERY clear boundaries and so far have been perfectly capable of sticking to them.
I feel like when you know where the boundaries are, it leaves you FREE to love appropriately. I think that perhaps where couples get into trouble is when they don't discuss (or share!) their vision of purity--or are without accountability--and gradually let things slide into other things. Time to get over prudishness and discuss this.