Are Macs really that much easier to work on?
Kind of hard to say, generally yes they are easier. I know people who have switched and are happy/suprised. I have used PCs and Macs alot, but pretty much just use my Macs now. Rarely touch PCs and it this point run Windows on my Mac the few times I need a PC program, which is limited. Some people may need PCs for their work depending on their IT department, etc., so keep that in mind
I have not been in love with Sony Vegas, probably mainly operator stupidity. I want to make HD & Blue Ray videos are Mac programs easier?
Will I have a problem with previous slide shows I have built with my PC loaded to the Web and my Website if I switch to a Mac?
blu-ray authoring/burning is not fully implemented on a Mac yet (if you think of full blown authoring) You will need a external burner. The new Final Cut Studio has some BR burning capabilites and enough to get blu-ray out. Ditto for Toast and Adobe Encore. Full blown authoring to tap into more of the blu-ray specs will require more. (And is pricey, but really for either platform. I think the lowest software for BR authoring runs about $3,000) I have not tried burning a BR project to standard DVD-R/+R (which could be done with DVD Studio Pro for HD DVD) but I think some people mentioned getting that to work on BR players, maybe with another system. I am not sure how much of an issue it really is since burners are dropping in price, but media is still a bit expensive. In other words, there is probably enough there to watch on blu-ray now but I would not replicate blu-ray discs without another system and testing, but enough to make blu-ray on a basic level.
Not sure how you made your slide shows or if somehow it is PC specific in terms of authoring or playback. From the playback side of things they will often work (and you can FTP the files up and down) but to edit the slideshows may not work if the software is not available for the Mac. (Though you maybe able to run the software on the Mac via Bootcamp or VM Ware)
That being said, even the iApps that come bundled with the Mac can do alot of things...
I know this is like Nikon vs. Canon but any insight is welcome.
Yeah it is goingto be like that. You will have fans from both sides and the arguments go on forever. Hey, when I read Wagsy's posts about Edius I am half tempted to buy a PC 
That being said, I do not see myself switching back to PCs. Who knows, there may be something so compelling at some point where PCs leave the Macs so far behind that there is no choice (or an easy choice) based on what I use my computers for, but right now, nope.