Can I use WD-40 on my bike? Is WD-40 really bad to apply on bikes? I was told so but still see people doing that. 

Also I saw WD-40 launching their new products of bike lubricant and degreaser. Did anybody try those?
WD-40 is mostly a solvent with a very light lubricant mixed in. It's great for getting stuck parts moving again. When you spray it on, the solvent dislodges whatever gunk may be causing the part to stick and then evaporates, leaving a light lubricant behind. This will allow the previously stuck part to move again. 

The reason it is generally not considered a good bicycle lubricant is because it is a light lubricant. It's just fine for household items like door hinges, which aren't exposed to weather and don't get moved a couple hundred times a minute. But the lubricant is not thick enough to adhere to rapidly moving bike parts for any length of time, especially when you add a little bit of road grit and/or rain.  

Some people do use it for loosening up shifters in the winter time (they stick when it's cold) or cleaning chains and derailleurs. You will notice in the answers and comments on the aforelinked question, and this one, that whether or not this is good practice is highly debatable. Some people will use WD-40 as a cleaner and degreaser followed by a bicycle-specific lubricant, with or without a cleaning inbetween, depending on personal preferences. 

I don't have any experience with their bicycle-specific products, but they're a solid company that's been in the business of cleaning and lubricating mechanical parts for a long time. They also make Lava soap and 3-in-1 Oil, a product that was originally designed as a bicycle lubricant (although they did acquire both of those from other companies). I actually didn't know until I read this question that they were making bicycle-specific lubricants now. Given their history and the number of patents that they have to draw ideas and develop from, I'm certainly willing to give them a shot. The worst case scenario is that I have to clean it off and go back to my previous products.