There are no serious issues legal wise. In this case that Luis has highlighted, and this stands in most countries (if not all) that I am aware of, a registered trademark takes precedence over any other local for of registration. So for example, if you had a registered business name with your local authority that in some way breached the registered trademark of a company, then they could pass on a cease and desist notification to you, requesting you not continue using that name.
If you chose to ignore it, then legal action could follow to enforce the trademark. You do hear of it happening, but it's usually when someone is trying to sail a little close to the wind in trying to gain mileage from a very well known product/service. It can be quite an effective marketing trick, but you have to be very careful not to step over the line or that's when they start taking notice of you.
So legally, I can't see any issue at all. Especially given that we are talking about a blog here, not some international fire breathing dragon. From a marketing/branding aspect, not great unfortunately. Individually as what can make you heard over all the other shouting voices and when your voice sounds like someone else's, then that can get confusing for customers.
That said, the worst that could happen is that someone Google searches your name and finds the blog or miss-types your name and hits the blog. So ensuring that you clearly identify your domain name is going to be super important to keep the traffic going to where it's supposed to. That said, the world of domain names is getting smaller every day and finding one that is completely unique from some one else is becoming a bit of a task.
So it's not something I would sweat about personally. Just be aware of it, make sure you concentrate on marketing your domain effectively and you should have clear winds ahead. Might be worth while remembering, it plays both well as well, if that blog is popular, then you may well end up with some miss-guided traffic hitting your site as well and who cares how they get there, so long as they buy something while they're there :)