Add name to title or just set up trust/will?

My mother has paid off her house finally this past year. She wants to add my name to the title of the house, that way when she passes, I would be in charge of what would happen to the house (I am the most responsible of her three children). I'm hesitant about doing this, because I'm not sure what sort of consequences I will suffer.

I know laws vary state by state (this is all in Virginia, by the way), but would anyone know generally the pros and cons of doing this? DH and I have never owned a home and probably will not buy one for a few years, but would my name being on the deed of the house affect that in any way (such as "first time homebuyer" perks)? Would I suffer from a "gift tax" or anything such as that since she is, in essence, "giving" me half the house? I keep telling her she just needs to set up a trust or her will stating that what exactly she wants done with it rather than put me on the title of the house, but I would like to be able to know what ramifications there are and let her know that this isn't the wisest choice, especially for me.

Thanks so much in advance - I'm a total noob to the whole real estate world!